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N-1A
NORTHERN INSTITUTIONAL FUNDS
2026-04-01
TREASURY PORTFOLIO—SHARES
INVESTMENT OBJECTIVE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio seeks to maximize current income to the extent consistent with the preservation of capital and maintenance of liquidity by investing its net assets, under normal market conditions, exclusively in U.S. Treasury securities and related repurchase agreements and other securities that limit their investments to, or are backed by, U.S. Treasury securities.</div>
FEES AND EXPENSES OF THE PORTFOLIO
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">This table describes the fees and expenses that you may pay if you buy, hold and sell Shares of the Portfolio. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Shares, which are not reflected in the tables or the examples below.</div>
Shareholder Fees (fees paid directly from your investment)
0
Annual Portfolio Operating Expenses (expenses that you pay each year asa percentage of the value of your investment)
0.0013
0.0002
0.0002
0
0.0000
0.0015
0.0000
0.0015
April 1, 2027
EXAMPLE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The following Example is intended to help you compare the cost of investing in Shares of the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Portfolio’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:</div>
15
48
85
192
PRINCIPAL INVESTMENT STRATEGIES
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio seeks to achieve its objective by investing, under normal circumstances, its total assets exclusively in:</div>
<table cellpadding="0" cellspacing="0" style="border-collapse: collapse; font-family: times new roman; font-size: 9.5pt; border-spacing: 0px; width: 100%;">
<tr style="page-break-inside: avoid;">
<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">Cash;</div> </td> </tr> </table>
<table cellpadding="0" cellspacing="0" style="border-collapse: collapse; font-family: times new roman; font-size: 9.5pt; border-spacing: 0px; width: 100%;">
<tr style="page-break-inside: avoid;">
<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">Short-term bills, notes, including floating rate notes, and other obligations issued or guaranteed by the U.S. Treasury (“Treasury Obligations”); and</div> </td> </tr> </table>
<table cellpadding="0" cellspacing="0" style="border-collapse: collapse; font-family: times new roman; font-size: 9.5pt; border-spacing: 0px; width: 100%;">
<tr style="page-break-inside: avoid;">
<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">Repurchase agreements collateralized fully by cash or Treasury Obligations.</div> </td> </tr> </table> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio, under normal circumstances, will invest at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in Treasury Obligations and repurchase agreements collateralized solely by Treasury Obligations. Repurchase agreements are agreements in which the Portfolio agrees to purchase portfolio securities from financial institutions subject to the seller’s agreement to repurchase them at a mutually agreed upon date and price.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio operates as a “government money market fund” under Rule 2a‑7 of the Investment Company Act of 1940, as amended. As a “government money market fund” under Rule 2a‑7, the Portfolio (1) is permitted to use the amortized cost method of valuation to seek to maintain a stable net asset value (“NAV”) of $1.00 share price, and (2) is not required to impose a liquidity fee on Portfolio redemptions that might apply to other types of money market funds. The Portfolio may invest in shares of other government money market funds.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Securities and Exchange Commission (“SEC”) imposes strict requirements on the investment quality, maturity, diversification and liquidity of the Portfolio’s investments. Accordingly, the Portfolio invests in U.S. dollar-denominated securities with a remaining maturity of no more than 397 days (with certain exceptions permitted by applicable regulations). The Portfolio maintains a dollar-weighted average portfolio maturity of no more than 60 calendar days, and a dollar-weighted average portfolio maturity as determined without</div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">exceptions regarding certain interest rate adjustments under Rule 2a‑7 of no more than 120 calendar days. The Portfolio will limit its investments to “eligible securities,” as defined by applicable regulations, at the time of acquisition (e.g., government securities, shares of other money market funds, and securities that present minimal credit risks as determined by NTI, pursuant to guidelines approved by the Portfolio’s Board of Trustees). The Portfolio may invest in variable and floating rate instruments. The Portfolio’s investment adviser may consider, among other things, credit and interest rate risks as well as general market conditions when deciding whether to buy or sell investments for the Portfolio. The Portfolio will generally hold a portion of its assets in cash to accommodate anticipated redemptions.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">STABLE NAV RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio will not be able to maintain a NAV per share of $1.00 at all times. A significant enough market disruption or drop in market prices of securities held by the Portfolio, especially at a time when the Portfolio needs to sell securities to meet shareholder redemption requests, could cause the value of the Portfolio’s shares to decrease to a price less than $1.00 per share. If the Portfolio fails to maintain a stable NAV (or if there is a perceived threat of such a failure) the Portfolio could be subject to increased redemption activity, which could adversely affect its NAV. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INTEREST RATE RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that during periods of rising interest rates, the market value of the Portfolio’s securities will tend to be lower than prevailing market rates and in periods of falling interest rates, the market value of the Portfolio’s securities will tend to be higher. The Portfolio’s yield will vary as short-term securities in its portfolio mature and the proceeds are reinvested in securities with different interest rates. In general, securities with longer maturities or durations are more sensitive to interest rate changes. A general rise in interest rates may cause investors to move out of fixed income securities on a large scale, which could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions for the Portfolio. During periods when inflation rates are high or rising, or during periods of low interest rates, the Portfolio may be subject to a greater risk of rising interest rates. Interest rate changes can be sudden and unpredictable and may have unpredictable effects on the markets and the Portfolio’s investment, may result in heightened market volatility, may impact the liquidity of fixed-income securities and of the Portfolio, and may detract from Portfolio performance. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">CREDIT (OR DEFAULT) RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the inability or unwillingness of an issuer or guarantor of a fixed-income security, or a counterparty to a repurchase or other transaction, to meet its principal or interest payments or other financial obligations in a timely manner will adversely affect the value of the Portfolio’s investments and its returns. Changes in an issuer’s financial strength, the market’s perception of an issuer’s creditworthiness, or in the credit rating of the issuer or the security may also affect the value of the Portfolio’s investment in that issuer. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">DEBT EXTENSION RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that when interest rates rise an issuer will exercise its right to pay principal on certain debt securities held by the Portfolio later than expected. This will cause the value of the security to decrease and the Portfolio may lose opportunities to invest in higher yielding securities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">VARIABLE OR FLOATING RATE INSTRUMENTS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that securities with variable or floating rates can be less sensitive to interest rate changes than securities with fixed interest rates, but may decline in value and negatively impact the Portfolio, particularly if changes in prevailing interest rates are more frequent or sudden than the rate changes for the variable or floating rate securities, which only occur periodically. Although variable and floating rate securities are less sensitive to interest rate risk than fixed-rate securities, they are subject to greater liquidity risk, which could impede their value. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INCOME RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio’s ability to distribute income to shareholders depends on the yield available from the Portfolio’s investments. Falling interest rates will cause the Portfolio’s income to decline. Income risk is generally higher for short-term debt securities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">REPURCHASE AGREEMENTS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the counterparty may default on its obligation to repurchase the underlying instruments collateralizing the repurchase agreement, which may cause the Portfolio to lose money. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INVESTMENT COMPANY RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio will be subject to the risks associated with investments in registered investment companies (“Underlying Funds”), such as the possibility that the value of the securities or instruments held by the Underlying Funds could decrease. Investments in Underlying Funds may involve duplication of management fees and certain other expenses, as the Portfolio indirectly bears its proportionate share of any expenses paid by the Underlying Funds in which it invests. NTI may be subject to potential conflicts of interest with respect to investments in affiliated Underlying Funds, which are Underlying Funds managed by NTI or its affiliates, because the fees </span></div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">paid to NTI by some affiliated Underlying Funds may be higher than the fees paid by other Underlying Funds.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">MARKET RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the value of the Portfolio’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Portfolio may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, elevated levels of government debt, changes in interest rates, lack of liquidity in the bond or equity markets or volatility in the equity markets. Market disruptions caused by local or regional events such as financial institution failures, changes in trade regulation or economic sanctions, internal unrest and discord, war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions, the threat or occurrence of a government shutdown, or other events or adverse investor sentiment could have a significant impact on the Portfolio and its investments. During periods of market disruption or other abnormal market conditions, the Portfolio’s exposure to risks described elsewhere in this summary will likely increase. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">CASH POSITIONS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that maintaining cash positions may negatively affect the Portfolio’s performance and potentially limit investment opportunities as a result of the Portfolio’s uninvested assets. Maintaining cash positions may also subject the Portfolio to increased credit risk exposure to the custodian bank. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">MANAGEMENT RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that a strategy used by the Portfolio’s investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">LARGE SHAREHOLDER RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that a large proportion of the interests of the Portfolio may be held by a small number of investors (or a single investor) and the Portfolio may experience adverse effects when certain large shareholders, including funds or accounts over which the Portfolio’s investment adviser or an affiliate of the investment adviser has investment discretion, purchase or redeem large amounts of shares of the Portfolio. Such large shareholder redemptions, which may occur rapidly and unexpectedly, may cause the Portfolio to sell its securities at times it would not otherwise do so, which may negatively impact its liquidity and/or NAV. Such sales may also accelerate the realization of taxable income to shareholders if these sales result in gains, and may also increase transaction costs. In addition, large redemptions could lead to an increase in the Portfolio’s expense ratio due to expenses being allocated over a smaller asset base. Large purchases of the Portfolio’s shares or having a more concentrated shareholder base may also adversely affect the Portfolio’s performance to the extent that the Portfolio is delayed in investing new cash or otherwise maintains a larger cash position than it ordinarily would. </span></div>
You could lose money by investing in the Portfolio.
Although the Portfolio seeks to preserve the value of your investment at $1.00 per share, the Portfolio cannot guarantee it will do so.
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman; font-weight: bold;">An investment in the Portfolio is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman; font-weight: bold;">The Portfolio’s sponsor is not required to reimburse the Portfolio for losses, and you should not expect that the sponsor will provide financial support to the Portfolio at any time, including during periods of market stress.</div>
PORTFOLIO PERFORMANCE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio’s Shares from year to year.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">Updated performance information for the Portfolio is available and may be obtained on the Portfolio’s website at https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance or by calling 800‑637‑1380.</div>
The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio’s Shares from year to year.
The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.
https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance
800‑637‑1380
CALENDAR YEAR TOTAL RETURNS (SHARES)*
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">* For the periods shown in the bar chart above: </span></div>
<table cellpadding="0" cellspacing="0" style="border-collapse: collapse; font-family: arial; font-size: 8pt; width: 100%; border-spacing: 0px; margin: 0 auto;">
<tr>
<td style="width: 63%;"></td>
<td style="vertical-align: bottom;"></td>
<td></td>
<td></td>
<td style="vertical-align: bottom; width: 2%;"></td>
<td style="vertical-align: bottom; width: 1%;"></td>
<td></td> </tr>
<tr style="page-break-inside: avoid; font-family: arial; font-size: 8pt; background-color: #cceeff;">
<td style="border: 0.75pt solid #000000; padding-left: 8pt; vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">highest quarterly return</div> </td>
<td style="border-left: 0.75pt solid #000000; border-top: 0.75pt solid #000000; border-bottom: 0.75pt solid #000000; vertical-align: bottom;"> </td>
<td style="border-top: 0.75pt solid #000000; border-bottom: 0.75pt solid #000000; vertical-align: bottom;"> </td>
<td style="border-top: 0.75pt solid #000000; border-bottom: 0.75pt solid #000000; vertical-align: bottom; text-align: right;">1.33</td>
<td style="border-top: 0.75pt solid #000000; border-bottom: 0.75pt solid #000000; white-space: nowrap; vertical-align: bottom;">% </td>
<td style="border-left: 0.75pt solid #000000; border-top: 0.75pt solid #000000; border-bottom: 0.75pt solid #000000; vertical-align: bottom;"> </td>
<td style="border-top: 0.75pt solid #000000; border-right: 0.75pt solid #000000; border-bottom: 0.75pt solid #000000; vertical-align: bottom;">fourth quarter of 2023</td> </tr>
<tr style="page-break-inside: avoid; font-family: arial; font-size: 8pt;">
<td style="border-left: 0.75pt solid #000000; border-right: 0.75pt solid #000000; border-bottom: 0.75pt solid #000000; padding-left: 8pt; vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">lowest quarterly return</div> </td>
<td style="border-left: 0.75pt solid #000000; border-bottom: 0.75pt solid #000000; vertical-align: bottom;"> </td>
<td style="border-bottom: 0.75pt solid #000000; vertical-align: bottom;"> </td>
<td style="border-bottom: 0.75pt solid #000000; vertical-align: bottom; text-align: right;">0.00</td>
<td style="border-bottom: 0.75pt solid #000000; white-space: nowrap; vertical-align: bottom;">% </td>
<td style="border-left: 0.75pt solid #000000; border-bottom: 0.75pt solid #000000; vertical-align: bottom;"> </td>
<td style="border-right: 0.75pt solid #000000; border-bottom: 0.75pt solid #000000; vertical-align: bottom;">first quarter of 2021</td> </tr> </table>
highest quarterly return
0.0133
2023-12-31
lowest quarterly return
0.0000
2021-03-31
AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, 2025)
0.0419
0.0312
0.0208
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">The 7‑day yield for Shares of the Portfolio as of December 31, 2025: 3.68%. For the current 7‑day yield call 800‑637‑1380 or visit https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#priceyield. </span></div>
The 7‑day yield for Shares of the Portfolio as of December 31, 2025:
0.0368
800‑637‑1380
TREASURY PORTFOLIO—SERVICE SHARES AND PREMIER SHARES
INVESTMENT OBJECTIVE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio seeks to maximize current income to the extent consistent with the preservation of capital and maintenance of liquidity by investing its net assets, under normal market conditions, exclusively in U.S. Treasury securities and related repurchase agreements and other securities that limit their investments to, or are backed by, U.S. Treasury securities.</div>
FEES AND EXPENSES OF THE PORTFOLIO
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">This table describes the fees and expenses that you may pay if you buy, hold, and sell Service Shares and Premier Shares of the Portfolio. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Service Shares, which are not reflected in the tables or the examples below.</div>
Shareholder Fees (fees paid directly from your investment)
0
0
Annual Portfolio Operating Expenses (expenses that you pay each year asa percentage of the value of your investment)
0.0013
0.0013
0.0002
0.0007
0.0002
0.0002
0
0.0005
0.0000
0.0000
0.0015
0.0020
0.0000
0.0000
0.0015
0.0020
“Other Expenses” are based on estimated amounts for the current fiscal year.
April 1, 2027
EXAMPLE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The following Example is intended to help you compare the cost of investing in Service Shares and Premier Shares of the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Portfolio’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:</div>
15
48
85
192
20
64
113
255
PRINCIPAL INVESTMENT STRATEGIES
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio seeks to achieve its objective by investing, under normal circumstances, its total assets exclusively in:</div>
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<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
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<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">Cash;</div> </td> </tr> </table>
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<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">Short-term bills, notes, including floating rate notes, and other obligations issued or guaranteed by the U.S. Treasury (“Treasury Obligations”); and</div> </td> </tr> </table>
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<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">Repurchase agreements collateralized fully by cash or Treasury Obligations.</div> </td> </tr> </table> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio, under normal circumstances, will invest at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in Treasury Obligations and repurchase agreements collateralized solely by Treasury Obligations. Repurchase agreements are agreements in which the Portfolio agrees to purchase portfolio securities from financial institutions subject to the seller’s agreement to repurchase them at a mutually agreed upon date and price.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio operates as a “government money market fund” under Rule 2a‑7 of the Investment Company Act of 1940, as amended. As a “government money market fund” under Rule 2a‑7, the Portfolio (1) is permitted to use the amortized cost method of valuation to seek to maintain a stable net asset value (“NAV”) of $1.00 share price, and (2) is not required to impose a liquidity fee on Portfolio redemptions that might apply to other types of money market funds. The Portfolio may invest in shares of other government money market funds.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Securities and Exchange Commission (“SEC”) imposes strict requirements on the investment quality, maturity, diversification and liquidity of the Portfolio’s investments. Accordingly, the Portfolio invests in U.S. dollar-denominated securities with a remaining maturity of no more than 397 days (with certain exceptions permitted by applicable regulations). The Portfolio maintains a dollar-weighted average portfolio maturity of no more than 60 calendar days, and a dollar-weighted average portfolio maturity as determined without</div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">exceptions regarding certain interest rate adjustments under Rule 2a‑7 of no more than 120 calendar days. The Portfolio will limit its investments to “eligible securities,” as defined by applicable regulations, at the time of acquisition (e.g., government securities, shares of other money market funds, and securities that present minimal credit risks as determined by NTI, pursuant to guidelines approved by the Portfolio’s Board of Trustees). The Portfolio may invest in variable and floating rate instruments. The Portfolio’s investment adviser may consider, among other things, credit and interest rate risks as well as general market conditions when deciding whether to buy or sell investments for the Portfolio. The Portfolio will generally hold a portion of its assets in cash to accommodate anticipated redemptions.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">STABLE NAV RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio will not be able to maintain a NAV per share of $1.00 at all times. A significant enough market disruption or drop in market prices of securities held by the Portfolio, especially at a time when the Portfolio needs to sell securities to meet shareholder redemption requests, could cause the value of the Portfolio’s shares to decrease to a price less than $1.00 per share. If the Portfolio fails to maintain a stable NAV (or if there is a perceived threat of such a failure) the Portfolio could be subject to increased redemption activity, which could adversely affect its NAV. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INTEREST RATE RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that during periods of rising interest rates, the market value of the Portfolio’s securities will tend to be lower than prevailing market rates and in periods of falling interest rates, the market value of the Portfolio’s securities will tend to be higher. The Portfolio’s yield will vary as short-term securities in its portfolio mature and the proceeds are reinvested in securities with different interest rates. In general, securities with longer maturities or durations are more sensitive to interest rate changes. A general rise in interest rates may cause investors to move out of fixed income securities on a large scale, which could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions for the Portfolio. During periods when inflation rates are high or rising, or during periods of low interest rates, the Portfolio may be subject to a greater risk of rising interest rates. Interest rate changes can be sudden and unpredictable and may have unpredictable effects on the markets and the Portfolio’s investment, may result in heightened market volatility, may impact the liquidity of fixed-income securities and of the Portfolio, and may detract from Portfolio performance. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">CREDIT (OR DEFAULT) RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the inability or unwillingness of an issuer or guarantor of a fixed-income security, or a counterparty to a repurchase or other transaction, to meet its principal or interest payments or other financial obligations in a timely manner will adversely affect the value of the Portfolio’s investments and its returns. Changes in an issuer’s financial strength, the market’s perception of an issuer’s creditworthiness, or in the credit rating of the issuer or the security may also affect the value of the Portfolio’s investment in that issuer. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">DEBT EXTENSION RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that when interest rates rise an issuer will exercise its right to pay principal on certain debt securities held by the Portfolio later than expected. This will cause the value of the security to decrease and the Portfolio may lose opportunities to invest in higher yielding securities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">VARIABLE OR FLOATING RATE INSTRUMENTS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that securities with variable or floating rates can be less sensitive to interest rate changes than securities with fixed interest rates, but may decline in value and negatively impact the Portfolio, particularly if changes in prevailing interest rates are more frequent or sudden than the rate changes for the variable or floating rate securities, which only occur periodically. Although variable and floating rate securities are less sensitive to interest rate risk than fixed-rate securities, they are subject to greater liquidity risk, which could impede their value. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INCOME RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio’s ability to distribute income to shareholders depends on the yield available from the Portfolio’s investments. Falling interest rates will cause the Portfolio’s income to decline. Income risk is generally higher for short-term debt securities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">REPURCHASE AGREEMENTS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the counterparty may default on its obligation to repurchase the underlying instruments collateralizing the repurchase agreement, which may cause the Portfolio to lose money. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INVESTMENT COMPANY RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio will be subject to the risks associated with investments in registered investment companies (“Underlying Funds”), such as the possibility that the value of the securities or instruments held by the Underlying Funds could decrease. Investments in Underlying Funds may involve duplication of management fees and certain other expenses, as the Portfolio indirectly bears its proportionate share of any expenses paid by the Underlying </span></div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">Funds in which it invests. NTI may be subject to potential conflicts of interest with respect to investments in affiliated Underlying Funds, which are Underlying Funds managed by NTI or its affiliates, because the fees paid to NTI by some affiliated Underlying Funds may be higher than the fees paid by other Underlying Funds.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">MARKET RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the value of the Portfolio’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Portfolio may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, elevated levels of government debt, changes in interest rates, lack of liquidity in the bond or equity markets or volatility in the equity markets Market disruptions caused by local or regional events such as financial institution failures, changes in trade regulation or economic sanctions, internal unrest and discord, war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions, the threat or occurrence of a government shutdown, or other events or adverse investor sentiment could have a significant impact on the Portfolio and its investments. During periods of market disruption or other abnormal market conditions, the Portfolio’s exposure to risks described elsewhere in this summary will likely increase. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">CASH POSITIONS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that maintaining cash positions may negatively affect the Portfolio’s performance and potentially limit investment opportunities as a result of the Portfolio’s uninvested assets. Maintaining cash positions may also subject the Portfolio to increased credit risk exposure to the custodian bank. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">MANAGEMENT RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that a strategy used by the Portfolio’s investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">LARGE SHAREHOLDER RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that a large proportion of the interests of the Portfolio may be held by a small number of investors (or a single investor) and the Portfolio may experience adverse effects when certain large shareholders, including funds or accounts over which the Portfolio’s investment adviser or an affiliate of the investment adviser has investment discretion, purchase or redeem large amounts of shares of the Portfolio. Such large shareholder redemptions, which may occur rapidly and unexpectedly, may cause the Portfolio to sell its securities at times it would not otherwise do so, which may negatively impact its liquidity and/or NAV. Such sales may also accelerate the realization of taxable income to shareholders if these sales result in gains, and may also increase transaction costs. In addition, large redemptions could lead to an increase in the Portfolio’s expense ratio due to expenses being allocated over a smaller asset base. Large purchases of the Portfolio’s shares or having a more concentrated shareholder base may also adversely affect the Portfolio’s performance to the extent that the Portfolio is delayed in investing new cash or otherwise maintains a larger cash position than it ordinarily would. </span></div>
You could lose money by investing in the Portfolio.
Although the Portfolio seeks to preserve the value of your investment at $1.00 per share, the Portfolio cannot guarantee it will do so.
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman; font-weight: bold;">An investment in the Portfolio is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman; font-weight: bold;">The Portfolio’s sponsor is not required to reimburse the Portfolio for losses, and you should not expect that the sponsor will provide financial support to the Portfolio at any time, including during periods of market stress.</div>
PORTFOLIO PERFORMANCE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio from year to year. As of December 31, 2025, there were no Service Shares outstanding for the Portfolio. Service Shares would have similar annual returns when compared with Premier Shares because each class is invested in the same portfolio of securities. The annual return of Premier Shares would differ from those of Service Shares only to the extent that the classes do not have the same expenses.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">Updated performance information for the Portfolio is available and may be obtained on the Portfolio’s website at https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance or by calling 800‑637‑1380.</div>
The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio from year to year.
The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.
https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance
800‑637‑1380
CALENDAR YEAR TOTAL RETURNS (PREMIER SHARES)*
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">* For the periods shown in the bar chart above: </span></div>
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<td style="border-left: 0.75pt solid #000000; border-top: 0.75pt solid #000000; border-bottom: 0.75pt solid #000000; padding-left: 8pt; vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">highest quarterly return</div> </td>
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<td style="border-top: 0.75pt solid #000000; border-bottom: 0.75pt solid #000000; vertical-align: bottom; text-align: right;">1.32</td>
<td style="border-top: 0.75pt solid #000000; border-bottom: 0.75pt solid #000000; white-space: nowrap; vertical-align: bottom;">% </td>
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<td style="border-top: 0.75pt solid #000000; border-bottom: 0.75pt solid #000000; vertical-align: bottom; text-align: right;">fourth quarter of 2023</td>
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<td style="border-left: 0.75pt solid #000000; border-bottom: 0.75pt solid #000000; padding-left: 8pt; vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">lowest quarterly return</div> </td>
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<td style="border-bottom: 0.75pt solid #000000; vertical-align: bottom; text-align: right;">0.00</td>
<td style="border-bottom: 0.75pt solid #000000; white-space: nowrap; vertical-align: bottom;">% </td>
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<td style="border-bottom: 0.75pt solid #000000; vertical-align: bottom; text-align: right;">fourth quarter of 2020</td>
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highest quarterly return
0.0132
2023-12-31
lowest quarterly return
0.0000
2020-12-31
AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, 2025)
2016-08-01
0.0413
0.0308
0.0216
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">The 7‑day yield for Premier Shares of the Portfolio as of December 31, 2025:3.63%. For the current 7‑day yield call 800‑637‑1380 or visit https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#priceyield. </span></div>
The 7‑day yield for Premier Shares of the Portfolio as of December 31, 2025:
0.0363
800‑637‑1380
TREASURY INSTRUMENTS PORTFOLIO—SHARES
INVESTMENT OBJECTIVE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio seeks to maximize current income to the extent consistent with the preservation of capital and maintenance of liquidity by investing its net assets, under normal conditions, exclusively in U.S. Treasury securities.</div>
FEES AND EXPENSES OF THE PORTFOLIO
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 10pt; font-family: times new roman;">This table describes the fees and expenses that you may pay if you buy, hold and sell Shares of the Portfolio. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Shares, which are not reflected in the tables or the examples below.</div>
Shareholder Fees (fees paid directly from your investment)
0
Annual Portfolio Operating Expenses (expenses that you pay each year asa percentage of the value of your investment)
0.0016
0.0002
0.0002
0
0.0000
0.0018
0.0000
0.0018
April 1, 2027
EXAMPLE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The following Example is intended to help you compare the cost of investing in Shares of the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Portfolio’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:</div>
18
58
101
230
PRINCIPAL INVESTMENT STRATEGIES
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 10pt; font-family: times new roman;">The Portfolio seeks to achieve its objective by investing, under normal circumstances, its total assets exclusively in:</div>
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<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
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<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">Cash; and</div> </td> </tr> </table>
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<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">Short-term bills, notes and other obligations issued or guaranteed by the U.S. Treasury (“Treasury Obligations”).</div> </td> </tr> </table> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio, under normal circumstances, will invest at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in Treasury Obligations. Repurchase agreements are agreements in which the Portfolio agrees to purchase portfolio securities from financial institutions subject to the seller’s agreement to repurchase them at a mutually agreed upon date and price.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio operates as a “government money market fund” under Rule 2a‑7 of the Investment Company Act of 1940, as amended. As a “government money market fund” under Rule 2a‑7, the Portfolio (1) is permitted to use the amortized cost method of valuation to seek to maintain a stable net asset value (“NAV”) of $1.00 share price, and (2) is not required to impose a liquidity fee on Portfolio redemptions that might apply to other types of money market funds. The Portfolio may invest in shares of other government money market funds.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Securities and Exchange Commission (“SEC”) imposes strict requirements on the investment quality, maturity, diversification and liquidity of the Portfolio’s investments. Accordingly, the Portfolio invests in U.S. dollar-denominated securities with a remaining maturity of no more than 397 days (with certain exceptions permitted by applicable regulations). The Portfolio maintains a dollar-weighted average portfolio maturity of no more than 60 calendar days, and a dollar-weighted average portfolio maturity as determined without</div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">exceptions regarding certain interest rate adjustments under Rule 2a‑7 of no more than 120 calendar days. The Portfolio will limit its investments to “eligible securities,” as defined by applicable regulations, at the time of acquisition (e.g., government securities, shares of other money market funds, and securities that present minimal credit risks as determined by NTI, pursuant to guidelines approved by the Portfolio’s Board of Trustees). The Portfolio may invest in variable and floating rate instruments. The Portfolio’s investment adviser may consider, among other things, credit and interest rate risks as well as general market conditions when deciding whether to buy or sell investments for the Portfolio. The Portfolio will generally hold a portion of its assets in cash to accommodate anticipated redemptions.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">STABLE NAV RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio will not be able to maintain a NAV per share of $1.00 at all times. A significant enough market disruption or drop in market prices of securities held by the Portfolio, especially at a time when the Portfolio needs to sell securities to meet shareholder redemption requests, could cause the value of the Portfolio’s shares to decrease to a price less than $1.00 per share. If the Portfolio fails to maintain a stable NAV (or if there is a perceived threat of such a failure) the Portfolio could be subject to increased redemption activity, which could adversely affect its NAV. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INTEREST RATE RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that during periods of rising interest rates, the market value of the Portfolio’s securities will tend to be lower than prevailing market rates and in periods of falling interest rates, the market value of the Portfolio’s securities will tend to be higher. The Portfolio’s yield will vary as short-term securities in its portfolio mature and the proceeds are reinvested in securities with different interest rates. In general, securities with longer maturities or durations are more sensitive to interest rate changes. A general rise in interest rates may cause investors to move out of fixed income securities on a large scale, which could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions for the Portfolio. During periods when inflation rates are high or rising, or during periods of low interest rates, the Portfolio may be subject to a greater risk of rising interest rates. Interest rate changes can be sudden and unpredictable and may have unpredictable effects on the markets and the Portfolio’s investment, may result in heightened market volatility, may impact the liquidity of fixed-income securities and of the Portfolio, and may detract from Portfolio performance. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">CREDIT (OR DEFAULT) RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the inability or unwillingness of an issuer or guarantor of a fixed-income security, or a counterparty to a repurchase or other transaction, to meet its principal or interest payments or other financial obligations in a timely manner will adversely affect the value of the Portfolio’s investments and its returns. Changes in an issuer’s financial strength, the market’s perception of an issuer’s creditworthiness, or in the credit rating of the issuer or the security may also affect the value of the Portfolio’s investment in that issuer. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">DEBT EXTENSION RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that when interest rates rise an issuer will exercise its right to pay principal on certain debt securities held by the Portfolio later than expected. This will cause the value of the security to decrease and the Portfolio may lose opportunities to invest in higher yielding securities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">VARIABLE OR FLOATING RATE INSTRUMENTS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that securities with variable or floating rates can be less sensitive to interest rate changes than securities with fixed interest rates, but may decline in value and negatively impact the Portfolio, particularly if changes in prevailing interest rates are more frequent or sudden than the rate changes for the variable or floating rate securities, which only occur periodically. Although variable and floating rate securities are less sensitive to interest rate risk than fixed-rate securities, they are subject to greater liquidity risk, which could impede their value. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INCOME RISK </span></span><span style="font-family: times new roman; font-size: 9.5pt;">is the risk that the Portfolio’s ability to distribute income to shareholders depends on the yield available from the Portfolio’s investments. Falling interest rates will cause the Portfolio’s income to decline. Income risk is generally higher for short-term debt securities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">LARGE SHAREHOLDER RISK </span></span><span style="font-family: times new roman; font-size: 9.5pt;">is the risk that a large proportion of the interests of the Portfolio may be held by a small number of investors (or a single investor) and the Portfolio may experience adverse effects when certain large shareholders, including funds or accounts over which the Portfolio’s investment adviser or an affiliate of the investment adviser has investment discretion, purchase or redeem large amounts of shares of the Portfolio. Such large shareholder redemptions, which may occur rapidly and unexpectedly, may cause the Portfolio to sell its securities at times it would not otherwise do so, which may negatively impact its liquidity and/or NAV. Such sales may also accelerate the realization of taxable income to </span></div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">shareholders if these sales result in gains, and may also increase transaction costs. In addition, large redemptions could lead to an increase in the Portfolio’s expense ratio due to expenses being allocated over a smaller asset base. Large purchases of the Portfolio’s shares or having a more concentrated shareholder base may also adversely affect the Portfolio’s performance to the extent that the Portfolio is delayed in investing new cash or otherwise maintains a larger cash position than it ordinarily would.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INVESTMENT COMPANY RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio will be subject to the risks associated with investments in registered investment companies (“Underlying Funds”), such as the possibility that the value of the securities or instruments held by the Underlying Funds could decrease. Investments in Underlying Funds may involve duplication of management fees and certain other expenses, as the Portfolio indirectly bears its proportionate share of any expenses paid by the Underlying Funds in which it invests. NTI may be subject to potential conflicts of interest with respect to investments in affiliated Underlying Funds, which are Underlying Funds managed by NTI or its affiliates, because the fees paid to NTI by some affiliated Underlying Funds may be higher than the fees paid by other Underlying Funds. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">MARKET RISK </span></span><span style="font-family: times new roman; font-size: 9.5pt;">is the risk that the value of the Portfolio’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Portfolio may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, elevated levels of government debt, changes in interest rates, lack of liquidity in the bond or equity markets or volatility in the equity markets. Market disruptions caused by local or regional events such as financial institution failures, changes in trade regulation or economic sanctions, internal unrest and discord, war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions, the threat or occurrence of a government shutdown, or other events or adverse investor sentiment could have a significant impact on the Portfolio and its investments. During periods of market disruption or other abnormal market conditions, the Portfolio’s exposure to risks described elsewhere in this summary will likely increase. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">CASH POSITIONS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that maintaining cash positions may negatively affect the Portfolio’s performance and potentially limit investment opportunities as a result of the Portfolio’s uninvested assets. Maintaining cash positions may also subject the Portfolio to increased credit risk exposure to the custodian bank. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">MANAGEMENT RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that a strategy used by the Portfolio’s investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results. </span></div>
You could lose money by investing in the Portfolio.
Although the Portfolio seeks to preserve the value of your investment at $1.00 per share, the Portfolio cannot guarantee it will do so.
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman; font-weight: bold;">An investment in the Portfolio is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman; font-weight: bold;">The Portfolio’s sponsor is not required to reimburse the Portfolio for losses, and you should not expect that the sponsor will provide financial support to the Portfolio at any time, including during periods of market stress.</div>
PORTFOLIO PERFORMANCE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio’s Shares from year to year.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">Updated performance information for the Portfolio is available and may be obtained on the Portfolio’s website at https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance or by calling 800‑637‑1380.</div>
The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio’s Shares from year to year.
The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.
https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance
800‑637‑1380
CALENDAR YEAR TOTAL RETURNS (SHARES)*
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">* For the periods shown in the bar chart above: </span></div>
<table cellpadding="0" cellspacing="0" style="border-collapse: collapse; font-family: arial; font-size: 8pt; width: 100%; border-spacing: 0px; margin: 0 auto;">
<tr>
<td style="width: 63%;"></td>
<td style="vertical-align: bottom;"></td>
<td></td>
<td></td>
<td style="vertical-align: bottom; width: 2%;"></td>
<td style="vertical-align: bottom; width: 1%;"></td>
<td></td> </tr>
<tr style="page-break-inside: avoid; font-family: arial; font-size: 8pt; background-color: #cceeff;">
<td style="vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">highest quarterly return</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom; text-align: right;">1.07</td>
<td style="white-space: nowrap; vertical-align: bottom;">% </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;">first quarter of 2025</td> </tr>
<tr style="page-break-inside: avoid; font-family: arial; font-size: 8pt;">
<td style="vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">lowest quarterly return</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom; text-align: right;">0.99</td>
<td style="white-space: nowrap; vertical-align: bottom;">% </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;">fourth quarter of 2025</td> </tr> </table>
highest quarterly return
0.0107
2025-03-31
lowest quarterly return
0.0099
2025-12-31
AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, 2025)
2024-10-07
0.0426
0.0435
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">The 7‑day yield for Shares of the Portfolio as of December 31, 2025: 3.75%. For the current 7‑day yield call 800‑637‑1380 or visit https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#priceyield. </span></div>
The 7‑day yield for Shares of the Portfolio as of December 31, 2025:
0.0375
800‑637‑1380
TREASURY INSTRUMENTS PORTFOLIO—SERVICE SHARES AND PREMIER SHARES
INVESTMENT OBJECTIVE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio seeks to maximize current income to the extent consistent with the preservation of capital and maintenance of liquidity by investing its net assets, under normal conditions, exclusively in U.S. Treasury securities.</div>
FEES AND EXPENSES OF THE PORTFOLIO
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 10pt; font-family: times new roman;">This table describes the fees and expenses that you may pay if you buy, hold, and sell Service Shares and Premier Shares of the Portfolio. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Service Shares, which are not reflected in the tables or the examples below.</div>
Shareholder Fees (fees paid directly from your investment)
0
0
Annual Portfolio Operating Expenses (expenses that you pay each year asa percentage of the value of your investment)
0.0016
0.0016
0.0002
0.0007
0.0002
0.0002
0
0.0005
0.0000
0.0000
0.0018
0.0023
0.0000
0.0000
0.0018
0.0023
“Other Expenses” are based on estimated amounts for the current fiscal year.
April 1, 2027
EXAMPLE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The following Example is intended to help you compare the cost of investing in Service Shares and Premier Shares of the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Portfolio’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:</div>
18
58
101
230
24
74
130
293
PRINCIPAL INVESTMENT STRATEGIES
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 10pt; font-family: times new roman;">The Portfolio seeks to achieve its objective by investing, under normal circumstances, its total assets exclusively in:</div>
<table cellpadding="0" cellspacing="0" style="border-collapse: collapse; font-family: times new roman; font-size: 9.5pt; border-spacing: 0px; width: 100%;">
<tr style="page-break-inside: avoid;">
<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">Cash; and</div> </td> </tr> </table>
<table cellpadding="0" cellspacing="0" style="border-collapse: collapse; font-family: times new roman; font-size: 9.5pt; border-spacing: 0px; width: 100%;">
<tr style="page-break-inside: avoid;">
<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">Short-term bills, notes and other obligations issued or guaranteed by the U.S. Treasury (“Treasury Obligations”).</div> </td> </tr> </table> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio, under normal circumstances, will invest at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in Treasury Obligations. Repurchase agreements are agreements in which the Portfolio agrees to purchase portfolio securities from financial institutions subject to the seller’s agreement to repurchase them at a mutually agreed upon date and price.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio operates as a “government money market fund” under Rule 2a‑7 of the Investment Company Act of 1940, as amended. As a “government money market fund” under Rule 2a‑7, the Portfolio (1) is permitted to use the amortized cost method of valuation to seek to maintain a stable net asset value (“NAV”) of $1.00 share price, and (2) is not required to impose a liquidity fee on Portfolio redemptions that might apply to other types of money market funds. The Portfolio may invest in shares of other government money market funds.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Securities and Exchange Commission (“SEC”) imposes strict requirements on the investment quality, maturity, diversification and liquidity of the Portfolio’s investments. Accordingly, the Portfolio invests in U.S. dollar-denominated securities with a remaining maturity of no more than 397 days (with certain exceptions permitted by applicable regulations). The Portfolio maintains a dollar-weighted average portfolio maturity of no more than 60 calendar days, and a dollar- weighted average portfolio maturity as determined without</div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">exceptions regarding certain interest rate adjustments under Rule 2a‑7 of no more than 120 calendar days. The Portfolio will limit its investments to “eligible securities,” as defined by applicable regulations, at the time of acquisition (e.g., government securities, shares of other money market funds, and securities that present minimal credit risks as determined by NTI, pursuant to guidelines approved by the Portfolio’s Board of Trustees). The Portfolio may invest in variable and floating rate instruments. The Portfolio’s investment adviser may consider, among other things, credit and interest rate risks as well as general market conditions when deciding whether to buy or sell investments for the Portfolio. The Portfolio will generally hold a portion of its assets in cash to accommodate anticipated redemptions.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">STABLE NAV RISK</span></span> is the risk that the Portfolio will not be able to maintain a NAV per share of $1.00 at all times. A significant enough market disruption or drop in market prices of securities held by the Portfolio, especially at a time when the Portfolio needs to sell securities to meet shareholder redemption requests, could cause the value of the Portfolio’s shares to decrease to a price less than $1.00 per share. If the Portfolio fails to maintain a stable NAV (or if there is a perceived threat of such a failure) the Portfolio could be subject to increased redemption activity, which could adversely affect its NAV.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">INTEREST RATE RISK</span></span> is the risk that during periods of rising interest rates, the market value of the Portfolio’s securities will tend to be lower than prevailing market rates and in periods of falling interest rates, the market value of the Portfolio’s securities will tend to be higher. The Portfolio’s yield will vary as short-term securities in its portfolio mature and the proceeds are reinvested in securities with different interest rates. In general, securities with longer maturities or durations are more sensitive to interest rate changes. A general rise in interest rates may cause investors to move out of fixed income securities on a large scale, which could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions for the Portfolio. During periods when inflation rates are high or rising, or during periods of low interest rates, the Portfolio may be subject to a greater risk of rising interest rates. Interest rate changes can be sudden and unpredictable and may have unpredictable effects on the markets and the Portfolio’s investment, may result in heightened market volatility, may impact the liquidity of fixed-income securities and of the Portfolio, and may detract from Portfolio performance.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">CREDIT (OR DEFAULT) RISK</span></span> is the risk that the inability or unwillingness of an issuer or guarantor of a fixed-income security, or a counterparty to a repurchase or other transaction, to meet its principal or interest payments or other financial obligations in a timely manner will adversely affect the value of the Portfolio’s investments and its returns. Changes in an issuer’s financial strength, the market’s perception of an issuer’s creditworthiness, or in the credit rating of the issuer or the security may also affect the value of the Portfolio’s investment in that issuer.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">DEBT EXTENSION RISK</span></span> is the risk that when interest rates rise an issuer will exercise its right to pay principal on certain debt securities held by the Portfolio later than expected. This will cause the value of the security to decrease and the Portfolio may lose opportunities to invest in higher yielding securities.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">VARIABLE OR FLOATING RATE INSTRUMENTS RISK</span></span> is the risk that securities with variable or floating rates can be less sensitive to interest rate changes than securities with fixed interest rates, but may decline in value and negatively impact the Portfolio, particularly if changes in prevailing interest rates are more frequent or sudden than the rate changes for the variable or floating rate securities, which only occur periodically. Although variable and floating rate securities are less sensitive to interest rate risk than fixed-rate securities, they are subject to greater liquidity risk, which could impede their value.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">INCOME RISK</span> </span>is the risk that the Portfolio’s ability to distribute income to shareholders depends on the yield available from the Portfolio’s investments. Falling interest rates will cause the Portfolio’s income to decline. Income risk is generally higher for short-term debt securities.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">LARGE SHAREHOLDER RISK</span></span> is the risk that a large proportion of the interests of the Portfolio may be held by a small number of investors (or a single investor) and the Portfolio may experience adverse effects when certain large shareholders, including funds or accounts over which the Portfolio’s investment adviser or an affiliate of the investment adviser has investment discretion, purchase or redeem large amounts of shares of the Portfolio. Such large shareholder redemptions, which may occur rapidly and unexpectedly, may cause the Portfolio to sell its securities at times it would not otherwise do so, which may negatively impact its liquidity and/or NAV. Such</div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">sales may also accelerate the realization of taxable income to shareholders if these sales result in gains, and may also increase transaction costs. In addition, large redemptions could lead to an increase in the Portfolio’s expense ratio due to expenses being allocated over a smaller asset base. Large purchases of the Portfolio’s shares or having a more concentrated shareholder base may also adversely affect the Portfolio’s performance to the extent that the Portfolio is delayed in investing new cash or otherwise maintains a larger cash position than it ordinarily would.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">INVESTMENT COMPANY RISK</span></span> is the risk that the Portfolio will be subject to the risks associated with investments in registered investment companies (“Underlying Funds”), such as the possibility that the value of the securities or instruments held by the Underlying Funds could decrease. Investments in Underlying Funds may involve duplication of management fees and certain other expenses, as the Portfolio indirectly bears its proportionate share of any expenses paid by the Underlying Funds in which it invests. NTI may be subject to potential conflicts of interest with respect to investments in affiliated Underlying Funds, which are Underlying Funds managed by NTI or its affiliates, because the fees paid to NTI by some affiliated Underlying Funds may be higher than the fees paid by other Underlying Funds.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">MARKET RISK</span></span> is the risk that the value of the Portfolio’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Portfolio may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, elevated levels of government debt, changes in interest rates, lack of liquidity in the bond or equity markets or volatility in the equity markets. Market disruptions caused by local or regional events such as financial institution failures, changes in trade regulation or economic sanctions, internal unrest and discord, war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions, the threat or occurrence of a government shutdown, or other events or adverse investor sentiment could have a significant impact on the Portfolio and its investments. During periods of market disruption or other abnormal market conditions, the Portfolio’s exposure to risks described elsewhere in this summary will likely increase.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">CASH POSITIONS RISK</span></span> is the risk that maintaining cash positions may negatively affect the Portfolio’s performance and potentially limit investment opportunities as a result of the Portfolio’s uninvested assets. Maintaining cash positions may also subject the Portfolio to increased credit risk exposure to the custodian bank.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">MANAGEMENT RISK</span></span> is the risk that a strategy used by the Portfolio’s investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results.</div>
You could lose money by investing in the Portfolio.
Although the Portfolio seeks to preserve the value of your investment at $1.00 per share, the Portfolio cannot guarantee it will do so.
An investment in the Portfolio is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;">The Portfolio’s sponsor is not required to reimburse the Portfolio for losses, and you should not expect that the sponsor will provide financial support to the Portfolio at any time, including during periods of market stress.</span></div>
PORTFOLIO PERFORMANCE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio from year to year. As of December 31, 2025, there were no Service Shares outstanding for the Portfolio. Service Shares would have similar annual returns when compared with Premier Shares because each class is invested in the same portfolio of securities. The annual return of Premier Shares would differ from those of Service Shares only to the extent that the classes do not have the same expenses.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">Updated performance information for the Portfolio is available and may be obtained on the Portfolio’s website at https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance or by calling 800‑637‑1380.</div>
The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio from year to year.
The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.
https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance
800‑637‑1380
CALENDAR YEAR TOTAL RETURNS (PREMIER SHARES)*
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">* For the periods shown in the bar chart above: </span></div>
<table cellpadding="0" cellspacing="0" style="border-collapse: collapse; font-family: arial; font-size: 8pt; width: 100%; border-spacing: 0px; margin: 0 auto;">
<tr>
<td style="width: 63%;"></td>
<td style="vertical-align: bottom;"></td>
<td></td>
<td></td>
<td style="vertical-align: bottom; width: 2%;"></td>
<td style="vertical-align: bottom; width: 1%;"></td>
<td></td> </tr>
<tr style="page-break-inside: avoid; font-family: arial; font-size: 8pt; background-color: #cceeff;">
<td style="vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">highest quarterly return</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom; text-align: right;">1.06</td>
<td style="white-space: nowrap; vertical-align: bottom;">% </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;">first quarter of 2025</td> </tr>
<tr style="page-break-inside: avoid; font-family: arial; font-size: 8pt;">
<td style="vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">lowest quarterly return</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom; text-align: right;">0.98</td>
<td style="white-space: nowrap; vertical-align: bottom;">% </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;">fourth quarter of 2025</td> </tr> </table>
highest quarterly return
0.0106
2025-03-31
lowest quarterly return
0.0098
2025-12-31
AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, 2025)
2024-06-11
0.0421
0.0449
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">The 7‑day yield for Premier Shares of the Portfolio as of December 31, 2025:3.70%. For the current 7‑day yield call 800‑637‑1380 or visit https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#priceyield. </span></div>
The 7‑day yield for Premier Shares of the Portfolio as of December 31, 2025:
0.0370
800‑637‑1380
U.S. GOVERNMENT PORTFOLIO—SHARES
INVESTMENT OBJECTIVE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio seeks to maximize current income to the extent consistent with the preservation of capital and maintenance of liquidity by investing exclusively in high quality money market instruments.</div>
FEES AND EXPENSES OF THE PORTFOLIO
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">This table describes the fees and expenses that you may pay if you buy, hold and sell Shares of the Portfolio. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Shares, which are not reflected in the tables or the examples below.</div>
Shareholder Fees (fees paid directly from your investment)
0
Annual Portfolio Operating Expenses (expenses that you pay each year asa percentage of the value of your investment)
0.0023
0.0003
0.0002
0
0.0001
0.0026
-0.0001
0.0025
April 1, 2027
EXAMPLE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The following Example is intended to help you compare the cost of investing in Shares of the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Portfolio’s operating expenses remain the same (taking into account the expense reimbursement arrangement for one year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:</div>
26
83
145
330
PRINCIPAL INVESTMENT STRATEGIES
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio seeks to achieve its objective by investing, under normal circumstances, substantially all (and at least 99.5%) of its total assets in cash, securities issued or guaranteed as to principal or interest by the U.S. government, its agencies, instrumentalities, or sponsored enterprises; and repurchase agreements that are fully collateralized by cash or government securities. The Portfolio, under normal circumstances, will invest at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in U.S. government securities and repurchase agreements collateralized solely by U.S. government securities. Repurchase agreements are agreements in which the Portfolio agrees to purchase portfolio securities from financial institutions subject to the seller’s agreement to repurchase them at a mutually agreed upon date and price.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio operates as a “government money market fund” under Rule 2a‑7 of the Investment Company Act of 1940, as amended. As a “government money market fund” under Rule 2a‑7, the Portfolio (1) is permitted to use the amortized cost method of valuation to seek to maintain a stable net asset value (“NAV”) of $1.00 share price, and (2) is not required to impose a liquidity fee on Portfolio redemptions that might apply to other types of money market funds. The Portfolio may invest in shares of other government money market funds.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Securities and Exchange Commission (“SEC”) imposes strict requirements on the investment quality, maturity, diversification and liquidity of the Portfolio’s investments. Accordingly, the Portfolio invests in U.S. dollar-denominated securities with a remaining maturity of no more than 397 days (with certain exceptions permitted by applicable regulations). The Portfolio maintains a dollar-weighted average portfolio maturity of no more than 60 calendar days, and a dollar-weighted average portfolio maturity as determined without exceptions regarding certain interest rate adjustments under Rule 2a‑7 of no more than 120 calendar days. The Portfolio will limit its investments to “eligible securities,” as defined by applicable regulations, at the time of acquisition (e.g., government securities, shares of other money market funds, and securities that present minimal credit risks as determined by NTI, pursuant to guidelines approved by the Portfolio’s Board of Trustees). The Portfolio may invest in variable and</div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">floating rate instruments. The Portfolio’s investment adviser may consider, among other things, credit, interest rate and prepayment risks as well as general market conditions when deciding whether to buy or sell investments for the Portfolio. The Portfolio will generally hold a portion of its assets in cash to accommodate anticipated redemptions.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">STABLE NAV RISK</span></span> is the risk that the Portfolio will not be able to maintain a NAV per share of $1.00 at all times. A significant enough market disruption or drop in market prices of securities held by the Portfolio, especially at a time when the Portfolio needs to sell securities to meet shareholder redemption requests, could cause the value of the Portfolio’s shares to decrease to a price less than $1.00 per share. If the Portfolio fails to maintain a stable NAV (or if there is a perceived threat of such a failure) the Portfolio could be subject to increased redemption activity, which could adversely affect its NAV.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">INTEREST RATE RISK</span></span> is the risk that during periods of rising interest rates, the market value of the Portfolio’s securities will tend to be lower than prevailing market rates and in periods of falling interest rates, the market value of the Portfolio’s securities will tend to be higher. The Portfolio’s yield will vary as short-term securities in its portfolio mature and the proceeds are reinvested in securities with different interest rates. In general, securities with longer maturities or durations are more sensitive to interest rate changes. A general rise in interest rates may cause investors to move out of fixed income securities on a large scale, which could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions for the Portfolio. During periods when inflation rates are high or rising, or during periods of low interest rates, the Portfolio may be subject to a greater risk of rising interest rates. Interest rate changes can be sudden and unpredictable and may have unpredictable effects on the markets and the Portfolio’s investment, may result in heightened market volatility, may impact the liquidity of fixed-income securities and of the Portfolio, and may detract from Portfolio performance.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">CREDIT (OR DEFAULT) RISK</span></span> is the risk that the inability or unwillingness of an issuer or guarantor of a fixed-income security, or a counterparty to a repurchase or other transaction, to meet its principal or interest payments or other financial obligations in a timely manner will adversely affect the value of the Portfolio’s investments and its returns. Changes in an issuer’s financial strength, the market’s perception of an issuer’s creditworthiness, or in the credit rating of the issuer or the security may also affect the value of the Portfolio’s investment in that issuer.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">DEBT EXTENSION RISK</span> </span>is the risk that when interest rates rise an issuer will exercise its right to pay principal on certain debt securities held by the Portfolio later than expected. This will cause the value of the security to decrease and the Portfolio may lose opportunities to invest in higher yielding securities.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">PREPAYMENT (OR CALL) RISK </span></span><span style="font-family: times new roman; font-size: 9.5pt;">is the risk that an issuer could exercise its right to pay principal on callable debt securities held by the Portfolio earlier than expected. Issuers may be more likely to prepay their securities if interest rates fall. If this happens, the Portfolio will not benefit from the rise in the market price of the securities that normally accompanies a decline in interest rates, and will be forced to reinvest prepayment proceeds in lower yielding securities, which may reduce the Portfolio’s returns. The Portfolio may also lose any premium it paid to purchase the securities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">VARIABLE OR FLOATING RATE INSTRUMENTS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that securities with variable or floating rates can be less sensitive to interest rate changes than securities with fixed interest rates, but may decline in value and negatively impact the Portfolio, particularly if changes in prevailing interest rates are more frequent or sudden than the rate changes for the variable or floating rate securities, which only occur periodically. Although variable and floating rate securities are less sensitive to interest rate risk than fixed-rate securities, they are subject to greater liquidity risk, which could impede their value. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INCOME RISK </span></span><span style="font-family: times new roman; font-size: 9.5pt;">is the risk that the Portfolio’s ability to distribute income to shareholders depends on the yield available from the Portfolio’s investments. Falling interest rates will cause the Portfolio’s income to decline. Income risk is generally higher for short-term debt securities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">U.S. GOVERNMENT SECURITIES RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the U.S. government will not provide financial support to its agencies, instrumentalities or sponsored enterprises if it is not obligated to do so by law. Certain U.S. government securities purchased by the Portfolio are neither issued nor guaranteed by the U.S. Treasury and, therefore, may not be backed by the full faith and credit of the United States. The maximum potential liability of the issuers of some U.S. government securities may greatly exceed their current resources, including any legal right to </span></div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">support from the U.S. Treasury. It is possible that the issuers of such securities will not have the funds to meet their payment obligations in the future. U.S. government securities include zero coupon securities, which tend to be subject to greater market risk than interest-paying securities of similar maturities.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">REPURCHASE AGREEMENTS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the counterparty may default on its obligation to repurchase the underlying instruments collateralizing the repurchase agreement, which may cause the Portfolio to lose money. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INVESTMENT COMPANY RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio will be subject to the risks associated with investments in registered investment companies (“Underlying Funds”), such as the possibility that the value of the securities or instruments held by the Underlying Funds could decrease. Investments in Underlying Funds may involve duplication of management fees and certain other expenses, as the Portfolio indirectly bears its proportionate share of any expenses paid by the Underlying Funds in which it invests. NTI may be subject to potential conflicts of interest with respect to investments in affiliated Underlying Funds, which are Underlying Funds managed by NTI or its affiliates, because the fees paid to NTI by some affiliated Underlying Funds may be higher than the fees paid by other Underlying Funds. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">MARKET RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the value of the Portfolio’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Portfolio may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, elevated levels of government debt, changes in interest rates, lack of liquidity in the bond or equity markets or volatility in the equity markets. Market disruptions caused by local or regional events such as financial institution failures, changes in trade regulation or economic sanctions, internal unrest and discord, war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions, the threat or occurrence of a government shutdown, or other events or adverse investor sentiment could have a significant impact on the Portfolio and its investments. During periods of market disruption or other abnormal market conditions, the Portfolio’s exposure to risks described elsewhere in this summary will likely increase. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">CASH POSITIONS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that maintaining cash positions may negatively affect the Portfolio’s performance and potentially limit investment opportunities as a result of the Portfolio’s uninvested assets. Maintaining cash positions may also subject the Portfolio to increased credit risk exposure to the custodian bank. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">MANAGEMENT RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that a strategy used by the Portfolio’s investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">LARGE SHAREHOLDER RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that a large proportion of the interests of the Portfolio may be held by a small number of investors (or a single investor) and the Portfolio may experience adverse effects when certain large shareholders, including funds or accounts over which the Portfolio’s investment adviser or an affiliate of the investment adviser has investment discretion, purchase or redeem large amounts of shares of the Portfolio. Such large shareholder redemptions, which may occur rapidly and unexpectedly, may cause the Portfolio to sell its securities at times it would not otherwise do so, which may negatively impact its liquidity and/or NAV. Such sales may also accelerate the realization of taxable income to shareholders if these sales result in gains, and may also increase transaction costs. In addition, large redemptions could lead to an increase in the Portfolio’s expense ratio due to expenses being allocated over a smaller asset base. Large purchases of the Portfolio’s shares or having a more concentrated shareholder base may also adversely affect the Portfolio’s performance to the extent that the Portfolio is delayed in investing new cash or otherwise maintains a larger cash position than it ordinarily would. </span></div>
You could lose money by investing in the Portfolio.
Although the Portfolio seeks to preserve the value of your investment at $1.00 per share, the Portfolio cannot guarantee it will do so.
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;">An investment in the Portfolio is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.</span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;">The Portfolio’s sponsor is not required to reimburse the Portfolio for losses, and you should not expect that the sponsor will provide financial support to the Portfolio at any time, including during periods of market stress.</span></div>
PORTFOLIO PERFORMANCE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio’s Shares from year to year.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">Updated performance information for the Portfolio is available and may be obtained on the Portfolio’s website at https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance or by calling 800‑637‑1380.</div>
The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio’s Shares from year to year.
The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.
https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance
800‑637‑1380
CALENDAR YEAR TOTAL RETURNS (SHARES)*
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">* For the periods shown in the bar chart above: </span></div>
<table cellpadding="0" cellspacing="0" style="border-collapse: collapse; font-family: arial; font-size: 8pt; width: 100%; border-spacing: 0px; margin: 0 auto;">
<tr>
<td style="width: 62%;"></td>
<td style="vertical-align: bottom;"></td>
<td></td>
<td></td>
<td style="vertical-align: bottom; width: 2%;"></td>
<td style="vertical-align: bottom; width: 1%;"></td>
<td></td> </tr>
<tr style="page-break-inside: avoid; font-family: arial; font-size: 8pt; background-color: #cceeff;">
<td style="vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">highest quarterly return</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom; text-align: right;">1.31</td>
<td style="white-space: nowrap; vertical-align: bottom;">% </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;">fourth quarter of 2023</td> </tr>
<tr style="page-break-inside: avoid; font-family: arial; font-size: 8pt;">
<td style="vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">lowest quarterly return</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom; text-align: right;">0.00</td>
<td style="white-space: nowrap; vertical-align: bottom;">% </td>
<td style="vertical-align: bottom;"> </td>
<td style="border-right: 0.75pt solid #000000; vertical-align: bottom;">second quarter of 2021</td> </tr> </table>
highest quarterly return
0.0131
2023-12-31
lowest quarterly return
0.0000
2021-06-30
AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, 2025)
0.0412
0.0306
0.0201
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">The 7‑day yield for Shares of the Portfolio as of December 31, 2025: 3.59%. For the current 7‑day yield call 800‑637‑1380 or visit https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#priceyield. </span></div>
The 7‑day yield for Shares of the Portfolio as of December 31, 2025:
0.0359
800‑637‑1380
U.S. GOVERNMENT PORTFOLIO—SERVICE AND PREMIER SHARES
INVESTMENT OBJECTIVE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio seeks to maximize current income to the extent consistent with the preservation of capital and maintenance of liquidity by investing exclusively in high quality money market instruments.</div>
FEES AND EXPENSES OF THE PORTFOLIO
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">This table describes the fees and expenses that you may pay if you buy, hold, and sell Service Shares and Premier Shares of the Portfolio. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Service Shares, which are not reflected in the tables or the examples below.</div>
Shareholder Fees (fees paid directly from your investment)
0
0
Annual Portfolio Operating Expenses (expenses that you pay each year asa percentage of the value of your investment)
0.0023
0.0023
0.0003
0.0003
0.0002
0.0002
0
0
0.0001
0.0001
0.0026
0.0026
-0.0001
-0.0001
0.0025
0.0025
“Other Expenses” are based on estimated amounts for the current fiscal year.
April 1, 2027
EXAMPLE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The following Example is intended to help you compare the cost of investing in Service Shares and Premier Shares of the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Portfolio’s operating expenses remain the same (taking into account the expense reimbursement arrangement for one year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:</div>
26
83
145
330
26
83
145
330
PRINCIPAL INVESTMENT STRATEGIES
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio seeks to achieve its objective by investing, under normal circumstances, substantially all (and at least 99.5%) of its total assets in cash, securities issued or guaranteed as to principal or interest by the U.S. government, its agencies, instrumentalities, or sponsored enterprises; and repurchase agreements that are fully collateralized by cash or government securities. The Portfolio, under normal circumstances, will invest at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in U.S. government securities and repurchase agreements collateralized solely by U.S. government securities. Repurchase agreements are agreements in which the Portfolio agrees to purchase portfolio securities from financial institutions subject to the seller’s agreement to repurchase them at a mutually agreed upon date and price.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio operates as a “government money market fund” under Rule 2a‑7 of the Investment Company Act of 1940, as amended. As a “government money market fund” under Rule 2a‑7, the Portfolio (1) is permitted to use the amortized cost method of valuation to seek to maintain a stable net asset value (“NAV”) of $1.00 share price, and (2) is not required to impose a liquidity fee on Portfolio redemptions that might apply to other types of money market funds. The Portfolio may invest in shares of other government money market funds.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Securities and Exchange Commission (“SEC”) imposes strict requirements on the investment quality, maturity, diversification and liquidity of the Portfolio’s investments. Accordingly, the Portfolio invests in U.S. dollar-denominated securities with a remaining maturity of no more than 397 days (with certain exceptions permitted by applicable regulations). The Portfolio maintains a dollar-weighted average portfolio maturity of no more than 60 calendar days, and a dollar-weighted average portfolio maturity as determined without exceptions regarding certain interest rate adjustments under Rule 2a‑7 of no more than 120 calendar days. The Portfolio will limit its investments to “eligible securities,” as defined by applicable regulations, at the time of acquisition (e.g., government securities, shares of other money market funds, and securities that present minimal credit risks as determined</div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">by NTI, pursuant to guidelines approved by the Portfolio’s Board of Trustees). The Portfolio may invest in variable and floating rate instruments. The Portfolio’s investment adviser may consider, among other things, credit, interest rate and prepayment risks as well as general market conditions when deciding whether to buy or sell investments for the Portfolio. The Portfolio will generally hold a portion of its assets in cash to accommodate anticipated redemptions.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">STABLE NAV RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio will not be able to maintain a NAV per share of $1.00 at all times. A significant enough market disruption or drop in market prices of securities held by the Portfolio, especially at a time when the Portfolio needs to sell securities to meet shareholder redemption requests, could cause the value of the Portfolio’s shares to decrease to a price less than $1.00 per share. If the Portfolio fails to maintain a stable NAV (or if there is a perceived threat of such a failure) the Portfolio could be subject to increased redemption activity, which could adversely affect its NAV. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INTEREST RATE RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that during periods of rising interest rates, the market value of the Portfolio’s securities will tend to be lower than prevailing market rates and in periods of falling interest rates, the market value of the Portfolio’s securities will tend to be higher. The Portfolio’s yield will vary as short-term securities in its portfolio mature and the proceeds are reinvested in securities with different interest rates. In general, securities with longer maturities or durations are more sensitive to interest rate changes. A general rise in interest rates may cause investors to move out of fixed income securities on a large scale, which could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions for the Portfolio. During periods when inflation rates are high or rising, or during periods of low interest rates, the Portfolio may be subject to a greater risk of rising interest rates. Interest rate changes can be sudden and unpredictable and may have unpredictable effects on the markets and the Portfolio’s investment, may result in heightened market volatility, may impact the liquidity of fixed-income securities and of the Portfolio, and may detract from Portfolio performance. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">CREDIT (OR DEFAULT) RISK</span></span> is the risk that the inability or unwillingness of an issuer or guarantor of a fixed-income security, or a counterparty to a repurchase or other transaction, to meet its principal or interest payments or other financial obligations in a timely manner will adversely affect the value of the Portfolio’s investments and its returns. Changes in an issuer’s financial strength, the market’s perception of an issuer’s creditworthiness, or in the credit rating of the issuer or the security may also affect the value of the Portfolio’s investment in that issuer.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">DEBT EXTENSION RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that when interest rates rise an issuer will exercise its right to pay principal on certain debt securities held by the Portfolio later than expected. This will cause the value of the security to decrease and the Portfolio may lose opportunities to invest in higher yielding securities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">PREPAYMENT (OR CALL) RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that an issuer could exercise its right to pay principal on callable debt securities held by the Portfolio earlier than expected. Issuers may be more likely to prepay their securities if interest rates fall. If this happens, the Portfolio will not benefit from the rise in the market price of the securities that normally accompanies a decline in interest rates, and will be forced to reinvest prepayment proceeds in lower yielding securities, which may reduce the Portfolio’s returns. The Portfolio may also lose any premium it paid to purchase the securities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">VARIABLE OR FLOATING RATE INSTRUMENTS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that securities with variable or floating rates can be less sensitive to interest rate changes than securities with fixed interest rates, but may decline in value and negatively impact the Portfolio, particularly if changes in prevailing interest rates are more frequent or sudden than the rate changes for the variable or floating rate securities, which only occur periodically. Although variable and floating rate securities are less sensitive to interest rate risk than fixed-rate securities, they are subject to greater liquidity risk, which could impede their value. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INCOME RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio’s ability to distribute income to shareholders depends on the yield available from the Portfolio’s investments. Falling interest rates will cause the Portfolio’s income to decline. Income risk is generally higher for short-term debt securities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">U.S. GOVERNMENT SECURITIES RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the U.S. government will not provide financial support to its agencies, instrumentalities or sponsored enterprises if it is not obligated to do so by law. Certain U.S. government securities purchased by the Portfolio are neither issued nor guaranteed by the U.S. Treasury and, therefore, may not be backed by the full faith and credit of the United States. The maximum potential liability of the issuers of some U.S. government securities may greatly exceed their current resources, including any legal right to </span></div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">support from the U.S. Treasury. It is possible that the issuers of such securities will not have the funds to meet their payment obligations in the future. U.S. government securities include zero coupon securities, which tend to be subject to greater market risk than interest-paying securities of similar maturities.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">REPURCHASE AGREEMENTS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the counterparty may default on its obligation to repurchase the underlying instruments collateralizing the repurchase agreement, which may cause the Portfolio to lose money. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INVESTMENT COMPANY RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio will be subject to the risks associated with investments in registered investment companies (“Underlying Funds”), such as the possibility that the value of the securities or instruments held by the Underlying Funds could decrease. Investments in Underlying Funds may involve duplication of management fees and certain other expenses, as the Portfolio indirectly bears its proportionate share of any expenses paid by the Underlying Funds in which it invests. NTI may be subject to potential conflicts of interest with respect to investments in affiliated Underlying Funds, which are Underlying Funds managed by NTI or its affiliates, because the fees paid to NTI by some affiliated Underlying Funds may be higher than the fees paid by other Underlying Funds. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">MARKET RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the value of the Portfolio’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Portfolio may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, elevated levels of government debt, changes in interest rates, lack of liquidity in the bond or equity markets or volatility in the equity markets. Market disruptions caused by local or regional events such as financial institution failures, changes in trade regulation or economic sanctions, internal unrest and discord, war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions, the threat or occurrence of a government shutdown, or other events or adverse investor sentiment could have a significant impact on the Portfolio and its investments. During periods of market disruption or other abnormal market conditions, the Portfolio’s exposure to risks described elsewhere in this summary will likely increase. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">CASH POSITIONS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that maintaining cash positions may negatively affect the Portfolio’s performance and potentially limit investment opportunities as a result of the Portfolio’s uninvested assets. Maintaining cash positions may also subject the Portfolio to increased credit risk exposure to the custodian bank. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">MANAGEMENT RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that a strategy used by the Portfolio’s investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">LARGE SHAREHOLDER RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that a large proportion of the interests of the Portfolio may be held by a small number of investors (or a single investor) and the Portfolio may experience adverse effects when certain large shareholders, including funds or accounts over which the Portfolio’s investment adviser or an affiliate of the investment adviser has investment discretion, purchase or redeem large amounts of shares of the Portfolio. Such large shareholder redemptions, which may occur rapidly and unexpectedly, may cause the Portfolio to sell its securities at times it would not otherwise do so, which may negatively impact its liquidity and/or NAV. Such sales may also accelerate the realization of taxable income to shareholders if these sales result in gains, and may also increase transaction costs. In addition, large redemptions could lead to an increase in the Portfolio’s expense ratio due to expenses being allocated over a smaller asset base. Large purchases of the Portfolio’s shares or having a more concentrated shareholder base may also adversely affect the Portfolio’s performance to the extent that the Portfolio is delayed in investing new cash or otherwise maintains a larger cash position than it ordinarily would. </span></div>
You could lose money by investing in the Portfolio.
Although the Portfolio seeks to preserve the value of your investment at $1.00 per share, the Portfolio cannot guarantee it will do so.
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman; font-weight: bold;">An investment in the Portfolio is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman; font-weight: bold;">The Portfolio’s sponsor is not required to reimburse the Portfolio for losses, and you should not expect that the sponsor will provide financial support to the Portfolio at any time, including during periods of market stress.</div>
PORTFOLIO PERFORMANCE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio from year to year. As of December 31, 2025, there were no Service Shares or Premier Shares outstanding for the Portfolio. The total return for periods prior to November 23, 2021, reflects the performance of the Portfolio’s Service Shares. On November 23, 2021, the Portfolio’s Service Shares ceased operations. Performance information after that date reflects that of the Portfolio’s Shares. Service Shares and Premier Shares would have similar</div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">annual returns when compared with Shares because each class is invested in the same portfolio of securities. The annual return of the Shares class would differ from those of Service Shares and Premier Shares only to the extent that the classes do not have the same expenses.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">Updated performance information for the Portfolio is available and may be obtained on the Portfolio’s website at https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance or by calling 800‑637‑1380.</div>
The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio from year to year.
The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.
https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance
800‑637‑1380
CALENDAR YEAR TOTAL RETURNS (SERVICE SHARES)*
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">* For the periods shown in the bar chart above: </span></div>
<table cellpadding="0" cellspacing="0" style="border-collapse: collapse; font-family: arial; font-size: 8pt; width: 100%; border-spacing: 0px; margin: 0 auto;">
<tr>
<td style="width: 62%;"></td>
<td style="vertical-align: bottom;"></td>
<td></td>
<td></td>
<td style="vertical-align: bottom; width: 2%;"></td>
<td style="vertical-align: bottom; width: 1%;"></td>
<td></td> </tr>
<tr style="page-break-inside: avoid; font-family: arial; font-size: 8pt; background-color: #cceeff;">
<td style="vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">highest quarterly return</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom; text-align: right;">1.31</td>
<td style="white-space: nowrap; vertical-align: bottom;">% </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;">fourth quarter of 2023</td> </tr>
<tr style="page-break-inside: avoid; font-family: arial; font-size: 8pt;">
<td style="vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">lowest quarterly return</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom; text-align: right;">0.00</td>
<td style="white-space: nowrap; vertical-align: bottom;">% </td>
<td style="vertical-align: bottom;"> </td>
<td style="border-right: 0.75pt solid #000000; vertical-align: bottom;">second quarter of 2021</td> </tr> </table>
highest quarterly return
0.0131
2023-12-31
lowest quarterly return
0.0000
2021-06-30
AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, 2025)
0.0412
0.0306
0.0201
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">The 7‑day yield for Shares of the Portfolio as of December 31, 2025: 3.59%. For the current 7‑day yield call 800‑637‑1380 or visit https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#priceyield. </span></div>
The 7‑day yield for Shares of the Portfolio as of December 31, 2025:
0.0359
800‑637‑1380
U.S. GOVERNMENT SELECT PORTFOLIO—SHARES
INVESTMENT OBJECTIVE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio seeks to maximize current income to the extent consistent with the preservation of capital and maintenance of liquidity by investing exclusively in high quality money market instruments.</div>
FEES AND EXPENSES OF THE PORTFOLIO
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">This table describes the fees and expenses that you may pay if you buy, hold and sell Shares of the Portfolio. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Shares, which are not reflected in the tables or the examples below.</div>
Shareholder Fees (fees paid directly from your investment)
0
Annual Portfolio Operating Expenses (expenses that you pay each year asa percentage of the value of your investment)
0.0018
0.0003
0.0002
0
0.0001
0.0021
-0.0001
0.0020
April 1, 2027
EXAMPLE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The following Example is intended to help you compare the cost of investing in Shares of the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Portfolio’s operating expenses remain the same (taking into account the expense reimbursement arrangement for one year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:</div>
20
67
117
267
PRINCIPAL INVESTMENT STRATEGIES
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio seeks to achieve its objective by investing, under normal circumstances, substantially all (and at least 99.5%) of its total assets in cash, securities issued or guaranteed as to principal or interest by the U.S. government, its agencies, instrumentalities, or sponsored enterprises; and repurchase agreements that are fully collateralized by cash or government securities. Subject to the foregoing 99.5% investment strategy requirement, under normal circumstances, the Portfolio will seek to invest at least 50% of its net assets in the following securities that pay interest that generally is exempt from state income taxation:</div>
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<tr style="page-break-inside: avoid;">
<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">U.S. Treasury bills;</div> </td> </tr> </table>
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<tr style="page-break-inside: avoid;">
<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">U.S. Treasury notes;</div> </td> </tr> </table>
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<tr style="page-break-inside: avoid;">
<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">U.S. Treasury STRIPS;</div> </td> </tr> </table>
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<tr style="page-break-inside: avoid;">
<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">securities issued by the Federal Home Loan Bank (FHLB);</div> </td> </tr> </table>
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<tr style="page-break-inside: avoid;">
<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">securities issued by the Federal Farm Credit Bank (FFCB); and</div> </td> </tr> </table>
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<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">securities issued by the Tennessee Valley Authority.</div> </td> </tr> </table> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio, under normal circumstances, will invest at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in U.S. government securities and repurchase agreements collateralized solely by U.S. government securities. Repurchase agreements are agreements in which the Portfolio agrees to purchase portfolio securities from financial institutions subject to the seller’s agreement to repurchase them at a mutually agreed upon date and price.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio operates as a “government money market fund” under Rule 2a‑7 of the Investment Company Act of 1940, as amended. As a “government money market fund” under Rule 2a‑7, the Portfolio (1) is permitted to use the amortized cost method of valuation to seek to maintain a stable net asset value (“NAV”) of $1.00 share price, and (2) is not required to impose a liquidity fee on Portfolio redemptions that might</div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">apply to other types of money market funds. The Portfolio may invest in shares of other government money market funds.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Securities and Exchange Commission (“SEC”) imposes strict requirements on the investment quality, maturity, diversification and liquidity of the Portfolio’s investments. Accordingly, the Portfolio invests in U.S. dollar-denominated securities with a remaining maturity of no more than 397 days (with certain exceptions permitted by applicable regulations). The Portfolio maintains a dollar-weighted average portfolio maturity of no more than 60 calendar days, and a dollar-weighted average portfolio maturity as determined without exceptions regarding certain interest rate adjustments under Rule 2a‑7 of no more than 120 calendar days. The Portfolio will limit its investments to “eligible securities,” as defined by applicable regulations, at the time of acquisition (e.g., government securities, shares of other money market funds, and securities that present minimal credit risks as determined by NTI, pursuant to guidelines approved by the Portfolio’s Board of Trustees). The Portfolio may invest in variable and floating rate instruments. The Portfolio’s investment adviser may consider, among other things, credit, interest rate and prepayment risks as well as general market conditions when deciding whether to buy or sell investments for the Portfolio. The Portfolio will generally hold a portion of its assets in cash to accommodate anticipated redemptions.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">STABLE NAV RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio will not be able to maintain a NAV per share of $1.00 at all times. A significant enough market disruption or drop in market prices of securities held by the Portfolio, especially at a time when the Portfolio needs to sell securities to meet shareholder redemption requests, could cause the value of the Portfolio’s shares to decrease to a price less than $1.00 per share. If the Portfolio fails to maintain a stable NAV (or if there is a perceived threat of such a failure) the Portfolio could be subject to increased redemption activity, which could adversely affect its NAV. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INTEREST RATE RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that during periods of rising interest rates, the market value of the Portfolio’s securities will tend to be lower than prevailing market rates and in periods of falling interest rates, the market value of the Portfolio’s securities will tend to be higher. The Portfolio’s yield will vary as short-term securities in its portfolio mature and the proceeds are reinvested in securities with different interest rates. In general, securities with longer maturities or durations are more sensitive to interest rate changes. A general rise in interest rates may cause investors to move out of fixed income securities on a large scale, which could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions for the Portfolio. During periods when inflation rates are high or rising, or during periods of low interest rates, the Portfolio may be subject to a greater risk of rising interest rates. Interest rate changes can be sudden and unpredictable and may have unpredictable effects on the markets and the Portfolio’s investment, may result in heightened market volatility, may impact the liquidity of fixed-income securities and of the Portfolio, and may detract from Portfolio performance. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">CREDIT (OR DEFAULT) RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the inability or unwillingness of an issuer or guarantor of a fixed-income security, or a counterparty to a repurchase or other transaction, to meet its principal or interest payments or other financial obligations in a timely manner will adversely affect the value of the Portfolio’s investments and its returns. Changes in an issuer’s financial strength, the market’s perception of an issuer’s creditworthiness, or in the credit rating of the issuer or the security may also affect the value of the Portfolio’s investment in that issuer. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">DEBT EXTENSION RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that when interest rates rise an issuer will exercise its right to pay principal on certain debt securities held by the Portfolio later than expected. This will cause the value of the security to decrease and the Portfolio may lose opportunities to invest in higher yielding securities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">PREPAYMENT (OR CALL) RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that an issuer could exercise its right to pay principal on callable debt securities held by the Portfolio earlier than expected. Issuers may be more likely to prepay their securities if interest rates fall. If this happens, the Portfolio will not benefit from the rise in the market price of the securities that normally accompanies a decline in interest rates, and will be forced to reinvest prepayment proceeds in lower yielding securities, which may reduce the Portfolio’s returns. The Portfolio may also lose any premium it paid to purchase the securities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">VARIABLE OR FLOATING RATE INSTRUMENTS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that securities with variable or floating rates can be less sensitive to interest rate changes than securities with fixed interest rates, but may decline in value and negatively impact the Portfolio, particularly if changes in prevailing interest rates are more frequent or sudden than the rate changes for the variable or </span></div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">floating rate securities, which only occur periodically. Although variable and floating rate securities are less sensitive to interest rate risk than fixed-rate securities, they are subject to greater liquidity risk, which could impede their value.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INCOME RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio’s ability to distribute income to shareholders depends on the yield available from the Portfolio’s investments. Falling interest rates will cause the Portfolio’s income to decline. Income risk is generally higher for short-term debt securities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">U.S. GOVERNMENT SECURITIES RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the U.S. government will not provide financial support to its agencies, instrumentalities or sponsored enterprises if it is not obligated to do so by law. Certain U.S. government securities purchased by the Portfolio are neither issued nor guaranteed by the U.S. Treasury and, therefore, may not be backed by the full faith and credit of the United States. The maximum potential liability of the issuers of some U.S. government securities may greatly exceed their current resources, including any legal right to support from the U.S. Treasury. It is possible that the issuers of such securities will not have the funds to meet their payment obligations in the future. U.S. government securities include zero coupon securities, which tend to be subject to greater market risk than interest-paying securities of similar maturities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">REPURCHASE AGREEMENTS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the counterparty may default on its obligation to repurchase the underlying instruments collateralizing the repurchase agreement, which may cause the Portfolio to lose money. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INVESTMENT COMPANY RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio will be subject to the risks associated with investments in registered investment companies (“Underlying Funds”), such as the possibility that the value of the securities or instruments held by the Underlying Funds could decrease. Investments in Underlying Funds may involve duplication of management fees and certain other expenses, as the Portfolio indirectly bears its proportionate share of any expenses paid by the Underlying Funds in which it invests. NTI may be subject to potential conflicts of interest with respect to investments in affiliated Underlying Funds, which are Underlying Funds managed by NTI or its affiliates, because the fees paid to NTI by some affiliated Underlying Funds may be higher than the fees paid by other Underlying Funds. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">MARKET RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the value of the Portfolio’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Portfolio may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, elevated levels of government debt, changes in interest rates, lack of liquidity in the bond or equity markets or volatility in the equity markets. Market disruptions caused by local or regional events such as financial institution failures, changes in trade regulation or economic sanctions, internal unrest and discord, war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions, the threat or occurrence of a government shutdown, or other events or adverse investor sentiment could have a significant impact on the Portfolio and its investments. During periods of market disruption or other abnormal market conditions, the Portfolio’s exposure to risks described elsewhere in this summary will likely increase. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">CASH POSITIONS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that maintaining cash positions may negatively affect the Portfolio’s performance and potentially limit investment opportunities as a result of the Portfolio’s uninvested assets. Maintaining cash positions may also subject the Portfolio to increased credit risk exposure to the custodian bank. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">MANAGEMENT RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that a strategy used by the Portfolio’s investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">LARGE SHAREHOLDER RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that a large proportion of the interests of the Portfolio may be held by a small number of investors (or a single investor) and the Portfolio may experience adverse effects when certain large shareholders, including funds or accounts over which the Portfolio’s investment adviser or an affiliate of the investment adviser has investment discretion, purchase or redeem large amounts of shares of the Portfolio. Such large shareholder redemptions, which may occur rapidly and unexpectedly, may cause the Portfolio to sell its securities at times it would not otherwise do so, which may negatively impact its liquidity and/or NAV. Such sales may also accelerate the realization of taxable income to shareholders if these sales result in gains, and may also increase transaction costs. In addition, large redemptions could lead to an increase in the Portfolio’s expense ratio due to expenses being allocated over a smaller asset base. Large purchases of the Portfolio’s shares or having a more concentrated shareholder base may also adversely affect the Portfolio’s performance to the extent that the Portfolio is delayed in investing new cash or otherwise maintains a larger cash position than it ordinarily would. </span></div>
You could lose money by investing in the Portfolio.
Although the Portfolio seeks to preserve the value of your investment at $1.00 per share, the Portfolio cannot guarantee it will do so.
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman; font-weight: bold;">An investment in the Portfolio is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.</div>
<div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman; font-weight: bold;">The Portfolio’s sponsor is not required to reimburse the Portfolio for losses, and you should not expect that the sponsor will provide financial support to the Portfolio at any time, including during periods of market stress.</div>
PORTFOLIO PERFORMANCE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio’s Shares from year to year.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">Updated performance information for the Portfolio is available and may be obtained on the Portfolio’s website at https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance or by calling 800‑637‑1380.</div>
The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio’s Shares from year to year.
The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.
https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance
800‑637‑1380
CALENDAR YEAR TOTAL RETURNS (SHARES)*
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">* For the periods shown in the bar chart above: </span></div>
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<tr>
<td style="width: 63%;"></td>
<td style="vertical-align: bottom;"></td>
<td></td>
<td></td>
<td style="vertical-align: bottom; width: 2%;"></td>
<td style="vertical-align: bottom; width: 1%;"></td>
<td></td> </tr>
<tr style="page-break-inside: avoid; font-family: arial; font-size: 8pt; background-color: #cceeff;">
<td style="vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">highest quarterly return</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom; text-align: right;">1.32</td>
<td style="white-space: nowrap; vertical-align: bottom;">% </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;">fourth quarter of 2023</td> </tr>
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<td style="vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">lowest quarterly return</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom; text-align: right;">0.00</td>
<td style="white-space: nowrap; vertical-align: bottom;">% </td>
<td style="vertical-align: bottom;"> </td>
<td style="border-right: 0.75pt solid #000000; vertical-align: bottom;">third quarter of 2020</td> </tr> </table>
highest quarterly return
0.0132
2023-12-31
lowest quarterly return
0.0000
2020-09-30
AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, 2025)
0.0420
0.0311
0.0206
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">The 7‑day yield for Shares of the Portfolio as of December 31, 2025: 3.66%. For the current 7‑day yield call 800‑637‑1380 or visit https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#priceyield. </span></div>
The 7‑day yield for Shares of the Portfolio as of December 31, 2025:
0.0366
800‑637‑1380
U.S. GOVERNMENT SELECT PORTFOLIO—SERVICE AND PREMIER SHARES
INVESTMENT OBJECTIVE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio seeks to maximize current income to the extent consistent with the preservation of capital and maintenance of liquidity by investing exclusively in high quality money market instruments.</div>
FEES AND EXPENSES OF THE PORTFOLIO
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">This table describes the fees and expenses that you may pay if you buy, hold, and sell Service Shares and Premier Shares of the Portfolio. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Service Shares, which are not reflected in the tables or the examples below.</div>
Shareholder Fees (fees paid directly from your investment)
0
0
Annual Portfolio Operating Expenses (expenses that you pay each year asa percentage of the value of your investment)
0.0018
0.0018
0.0003
0.0003
0.0002
0.0002
0
0
0.0001
0.0001
0.0021
0.0021
-0.0001
-0.0001
0.0020
0.0020
“Other Expenses” are based on estimated amounts for the current fiscal year.
April 1, 2027
EXAMPLE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The following Example is intended to help you compare the cost of investing in Service Shares and Premier Shares of the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Portfolio’s operating expenses remain the same (taking into account the expense reimbursement arrangement for one year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:</div>
20
67
117
267
20
67
117
267
PRINCIPAL INVESTMENT STRATEGIES
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio seeks to achieve its objective by investing, under normal circumstances, substantially all (and at least 99.5%) of its total assets in cash, securities issued or guaranteed as to principal or interest by the U.S. government, its agencies, instrumentalities, or sponsored enterprises; and repurchase agreements that are fully collateralized by cash or government securities. Subject to the foregoing 99.5% investment strategy requirement, under normal circumstances, the Portfolio will seek to invest at least 50% of its net assets in the following securities that pay interest that generally is exempt from state income taxation:</div>
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<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">U.S. Treasury bills;</div> </td> </tr> </table>
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<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">U.S. Treasury notes;</div> </td> </tr> </table>
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<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">U.S. Treasury STRIPS;</div> </td> </tr> </table>
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<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">securities issued by the Federal Home Loan Bank (FHLB);</div> </td> </tr> </table>
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<tr style="page-break-inside: avoid;">
<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">securities issued by the Federal Farm Credit Bank (FFCB); and</div> </td> </tr> </table>
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<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">securities issued by the Tennessee Valley Authority.</div> </td> </tr> </table> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio, under normal circumstances, will invest at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in U.S. government securities and repurchase agreements collateralized solely by U.S. government securities. Repurchase agreements are agreements in which the Portfolio agrees to purchase portfolio securities from financial institutions subject to the seller’s agreement to repurchase them at a mutually agreed upon date and price.</div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio operates as a “government money market fund” under Rule 2a‑7 of the Investment Company Act of 1940, as amended. As a “government money market fund” under Rule 2a‑7, the Portfolio (1) is permitted to use the amortized cost method of valuation to seek to maintain a stable net asset value (“NAV”) of $1.00 share price, and (2) is not required to impose a liquidity fee on Portfolio redemptions that might apply to other types of money market funds. The Portfolio may invest in shares of other government money market funds.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Securities and Exchange Commission (“SEC”) imposes strict requirements on the investment quality, maturity, diversification and liquidity of the Portfolio’s investments. Accordingly, the Portfolio invests in U.S. dollar-denominated securities with a remaining maturity of no more than 397 days (with certain exceptions permitted by applicable regulations). The Portfolio maintains a dollar-weighted average portfolio maturity of no more than 60 calendar days, and a dollar-weighted average portfolio maturity as determined without exceptions regarding certain interest rate adjustments under Rule 2a‑7 of no more than 120 calendar days. The Portfolio will limit its investments to “eligible securities,” as defined by applicable regulations, at the time of acquisition (e.g., government securities, shares of other money market funds, and securities that present minimal credit risks as determined by NTI, pursuant to guidelines approved by the Portfolio’s Board of Trustees). The Portfolio may invest in variable and floating rate instruments. The Portfolio’s investment adviser may consider, among other things, credit, interest rate and prepayment risks as well as general market conditions when deciding whether to buy or sell investments for the Portfolio. The Portfolio will generally hold a portion of its assets in cash to accommodate anticipated redemptions.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">STABLE NAV RISK</span></span> is the risk that the Portfolio will not be able to maintain a NAV per share of $1.00 at all times. A significant enough market disruption or drop in market prices of securities held by the Portfolio, especially at a time when the Portfolio needs to sell securities to meet shareholder redemption requests, could cause the value of the Portfolio’s shares to decrease to a price less than $1.00 per share. If the Portfolio fails to maintain a stable NAV (or if there is a perceived threat of such a failure) the Portfolio could be subject to increased redemption activity, which could adversely affect its NAV.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">INTEREST RATE RISK</span></span> is the risk that during periods of rising interest rates, the market value of the Portfolio’s securities will tend to be lower than prevailing market rates and in periods of falling interest rates, the market value of the Portfolio’s securities will tend to be higher. The Portfolio’s yield will vary as short-term securities in its portfolio mature and the proceeds are reinvested in securities with different interest rates. In general, securities with longer maturities or durations are more sensitive to interest rate changes. A general rise in interest rates may cause investors to move out of fixed income securities on a large scale, which could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions for the Portfolio. During periods when inflation rates are high or rising, or during periods of low interest rates, the Portfolio may be subject to a greater risk of rising interest rates. Interest rate changes can be sudden and unpredictable and may have unpredictable effects on the markets and the Portfolio’s investment, may result in heightened market volatility, may impact the liquidity of fixed-income securities and of the Portfolio, and may detract from Portfolio performance.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">CREDIT (OR DEFAULT) RISK</span></span> is the risk that the inability or unwillingness of an issuer or guarantor of a fixed-income security, or a counterparty to a repurchase or other transaction, to meet its principal or interest payments or other financial obligations in a timely manner will adversely affect the value of the Portfolio’s investments and its returns. Changes in an issuer’s financial strength, the market’s perception of an issuer’s creditworthiness, or in the credit rating of the issuer or the security may also affect the value of the Portfolio’s investment in that issuer.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">DEBT EXTENSION RISK</span></span> is the risk that when interest rates rise an issuer will exercise its right to pay principal on certain debt securities held by the Portfolio later than expected. This will cause the value of the security to decrease and the Portfolio may lose opportunities to invest in higher yielding securities.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">PREPAYMENT (OR CALL) RISK</span></span> is the risk that an issuer could exercise its right to pay principal on callable debt securities held by the Portfolio earlier than expected. Issuers may be more likely to prepay their securities if interest rates fall. If this happens, the Portfolio will not benefit from the rise in the market price of the securities that normally accompanies a decline in interest rates, and will be forced to reinvest prepayment proceeds in lower yielding securities, which may</div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">reduce the Portfolio’s returns. The Portfolio may also lose any premium it paid to purchase the securities.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">VARIABLE OR FLOATING RATE INSTRUMENTS RISK</span></span> is the risk that securities with variable or floating rates can be less sensitive to interest rate changes than securities with fixed interest rates, but may decline in value and negatively impact the Portfolio, particularly if changes in prevailing interest rates are more frequent or sudden than the rate changes for the variable or floating rate securities, which only occur periodically. Although variable and floating rate securities are less sensitive to interest rate risk than fixed-rate securities, they are subject to greater liquidity risk, which could impede their value.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INCOME RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio’s ability to distribute income to shareholders depends on the yield available from the Portfolio’s investments. Falling interest rates will cause the Portfolio’s income to decline. Income risk is generally higher for short-term debt securities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">U.S. GOVERNMENT SECURITIES RISK</span></span> is the risk that the U.S. government will not provide financial support to its agencies, instrumentalities or sponsored enterprises if it is not obligated to do so by law. Certain U.S. government securities purchased by the Portfolio are neither issued nor guaranteed by the U.S. Treasury and, therefore, may not be backed by the full faith and credit of the United States. The maximum potential liability of the issuers of some U.S. government securities may greatly exceed their current resources, including any legal right to support from the U.S. Treasury. It is possible that the issuers of such securities will not have the funds to meet their payment obligations in the future. U.S. government securities include zero coupon securities, which tend to be subject to greater market risk than interest-paying securities of similar maturities.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">REPURCHASE AGREEMENTS RISK</span></span> is the risk that the counterparty may default on its obligation to repurchase the underlying instruments collateralizing the repurchase agreement, which may cause the Portfolio to lose money.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">INVESTMENT COMPANY RISK</span></span> is the risk that the Portfolio will be subject to the risks associated with investments in registered investment companies (“Underlying Funds”), such as the possibility that the value of the securities or instruments held by the Underlying Funds could decrease. Investments in Underlying Funds may involve duplication of management fees and certain other expenses, as the Portfolio indirectly bears its proportionate share of any expenses paid by the Underlying Funds in which it invests. NTI may be subject to potential conflicts of interest with respect to investments in affiliated Underlying Funds, which are Underlying Funds managed by NTI or its affiliates, because the fees paid to NTI by some affiliated Underlying Funds may be higher than the fees paid by other Underlying Funds.</div>
<div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">MARKET RISK</span></span> is the risk that the value of the Portfolio’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Portfolio may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, elevated levels of government debt, changes in interest rates, lack of liquidity in the bond or equity markets or volatility in the equity markets. Market disruptions caused by local or regional events such as financial institution failures, changes in trade regulation or economic sanctions, internal unrest and discord, war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions, the threat or occurrence of a government shutdown, or other events or adverse investor sentiment could have a significant impact on the Portfolio and its investments. During periods of market disruption or other abnormal market conditions, the Portfolio’s exposure to risks described elsewhere in this summary will likely increase.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">CASH POSITIONS RISK</span></span> is the risk that maintaining cash positions may negatively affect the Portfolio’s performance and potentially limit investment opportunities as a result of the Portfolio’s uninvested assets. Maintaining cash positions may also subject the Portfolio to increased credit risk exposure to the custodian bank.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">MANAGEMENT RISK</span></span> is the risk that a strategy used by the Portfolio’s investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">LARGE SHAREHOLDER RISK</span></span> is the risk that a large proportion of the interests of the Portfolio may be held by a small number of investors (or a single investor) and the Portfolio may experience adverse effects when certain large shareholders, including funds or accounts over which the Portfolio’s investment adviser or an affiliate of the investment adviser has investment discretion, purchase or redeem large amounts of shares of the Portfolio. Such large shareholder redemptions, which may occur rapidly and unexpectedly, may cause the Portfolio to sell its securities at times it would not otherwise do so, which may negatively impact its liquidity and/or NAV. Such sales may also accelerate the realization of taxable income to shareholders if these sales result in gains, and may also increase transaction costs. In addition, large redemptions could lead to an increase in the Portfolio’s expense ratio due to expenses being allocated over a smaller asset base. Large purchases of the Portfolio’s shares or having a more concentrated shareholder base may also adversely affect the Portfolio’s performance to</div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">the extent that the Portfolio is delayed in investing new cash or otherwise maintains a larger cash position than it ordinarily would.</div>
You could lose money by investing in the Portfolio.
Although the Portfolio seeks to preserve the value of your investment at $1.00 per share, the Portfolio cannot guarantee it will do so.
An investment in the Portfolio is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.
The Portfolio’s sponsor is not required to reimburse the Portfolio for losses, and you should not expect that the sponsor will provide financial support to the Portfolio at any time, including during periods of market stress.
PORTFOLIO PERFORMANCE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio from year to year. As of December 31, 2025, there were no Premier Shares outstanding for the Portfolio. Premier Shares would have similar annual returns when compared with Service Shares because each class is invested in the same portfolio of securities. The annual return of Service Shares would differ from those of Premier Shares only to the extent that the classes do not have the same expenses.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.</div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">Updated performance information for the Portfolio is available and may be obtained on the Portfolio’s website at https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#priceyield or by calling 800‑637‑1380.</div>
The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio from year to year.
The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.
https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#priceyield
800‑637‑1380
CALENDAR YEAR TOTAL RETURNS (SERVICE SHARES)*
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">* For the periods shown in the bar chart above: </span></div>
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<tr>
<td style="width: 63%;"></td>
<td style="vertical-align: bottom;"></td>
<td></td>
<td></td>
<td style="vertical-align: bottom; width: 2%;"></td>
<td style="vertical-align: bottom; width: 1%;"></td>
<td></td> </tr>
<tr style="page-break-inside: avoid; font-family: arial; font-size: 8pt; background-color: #cceeff;">
<td style="vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">highest quarterly return</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom; text-align: right;">1.32</td>
<td style="white-space: nowrap; vertical-align: bottom;">% </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;">fourth quarter of 2023</td> </tr>
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<td style="vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">lowest quarterly return</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom; text-align: right;">0.00</td>
<td style="white-space: nowrap; vertical-align: bottom;">% </td>
<td style="vertical-align: bottom;"> </td>
<td style="border-right: 0.75pt solid #000000; vertical-align: bottom;">third quarter of 2020</td> </tr> </table>
highest quarterly return
0.0132
2023-12-31
lowest quarterly return
0.0000
2020-09-30
AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, 2025)
0.0420
0.0311
0.0206
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">The 7‑day yield for Service Shares of the Portfolio as of December 31, 2025: 3.66%. For the current 7‑day yield call 800‑637‑1380 or visit https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance. </span></div>
The 7‑day yield for Service Shares of the Portfolio as of December 31, 2025:
0.0366
800‑637‑1380
TREASURY PORTFOLIO
INVESTMENT OBJECTIVE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio seeks to maximize current income to the extent consistent with the preservation of capital and maintenance of liquidity by investing its net assets, under normal market conditions, exclusively in U.S. Treasury securities and related repurchase agreements and other securities that limit their investments to, or are backed by, U.S. Treasury securities.</div>
FEES AND EXPENSES OF THE PORTFOLIO
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">This table describes the fees and expenses that you may pay if you buy, hold and sell Siebert Williams Shank Shares of the Portfolio. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Siebert Williams Shank Shares, which are not reflected in the tables or the examples below.</div>
Shareholder Fees (fees paid directly from your investment)
0
Annual Portfolio Operating Expenses (expenses that you pay each year asa percentage of the value of your investment)
0.0013
0.0002
0.0002
0
0
0.0015
0.0000
0.0015
April 1, 2027
EXAMPLE
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The following Example is intended to help you compare the cost of investing in Siebert Williams Shank Shares of the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Portfolio’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:</div>
15
48
85
192
PRINCIPAL INVESTMENT STRATEGIES
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio seeks to achieve its objective by investing, under normal circumstances, its total assets exclusively in:</div>
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<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">Cash;</div> </td> </tr> </table>
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<tr style="page-break-inside: avoid;">
<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">Short-term bills, notes, including floating rate notes, and other obligations issued or guaranteed by the U.S. Treasury (“Treasury Obligations”); and</div> </td> </tr> </table>
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<tr style="page-break-inside: avoid;">
<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">Repurchase agreements collateralized fully by cash or Treasury Obligations.</div> </td> </tr> </table> <div style="margin-top: 5pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio, under normal circumstances, will invest at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in Treasury Obligations and repurchase agreements collateralized solely by Treasury Obligations. Repurchase agreements are agreements in which the Portfolio agrees to purchase portfolio securities from financial institutions subject to the seller’s agreement to repurchase them at a mutually agreed upon date and price.</div> <div style="margin-top: 5pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio operates as a “government money market fund” under Rule 2a‑7 of the Investment Company Act of 1940, as amended. As a “government money market fund” under Rule 2a‑7, the Portfolio (wo1) is permitted to use the amortized cost method of valuation to seek to maintain a stable net asset value (“NAV”) of $1.00 share price, and (2) is not required to impose a liquidity fee on Portfolio redemptions that might apply to other types of money market funds. The Portfolio may invest in shares of other government money market funds.</div> <div style="margin-top: 5pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Securities and Exchange Commission (“SEC”) imposes strict requirements on the investment quality, maturity, diversification and liquidity of the Portfolio’s investments. Accordingly, the Portfolio invests in U.S. dollar-denominated securities with a remaining maturity of no more than 397 days (with certain exceptions permitted by applicable regulations). The Portfolio maintains a dollar-weighted average portfolio maturity of no more than 60 calendar days, and a dollar-weighted average portfolio maturity as determined without</div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">exceptions regarding certain interest rate adjustments under Rule 2a‑7 of no more than 120 calendar days. The Portfolio will limit its investments to “eligible securities,” as defined by applicable regulations, at the time of acquisition (e.g., government securities, shares of other money market funds, and securities that present minimal credit risks as determined by NTI, pursuant to guidelines approved by the Portfolio’s Board of Trustees). The Portfolio may invest in variable and floating rate instruments. The Portfolio’s investment adviser may consider, among other things, credit and interest rate risks as well as general market conditions when deciding whether to buy or sell investments for the Portfolio. The Portfolio will generally hold a portion of its assets in cash to accommodate anticipated redemptions.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">STABLE NAV RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio will not be able to maintain a NAV per share of $1.00 at all times. A significant enough market disruption or drop in market prices of securities held by the Portfolio, especially at a time when the Portfolio needs to sell securities to meet shareholder redemption requests, could cause the value of the Portfolio’s shares to decrease to a price less than $1.00 per share. If the Portfolio fails to maintain a stable NAV (or if there is a perceived threat of such a failure) the Portfolio could be subject to increased redemption activity, which could adversely affect its NAV. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INTEREST RATE RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that during periods of rising interest rates, the market value of a Portfolio’s securities will tend to be lower than prevailing market rates and in periods of falling interest rates, the market value of a Portfolio’s securities will tend to be higher. A Portfolio’s yield will vary as short-term securities in its portfolio mature and the proceeds are reinvested in securities with different interest rates. In general, securities with longer maturities or durations are more sensitive to interest rate changes. A general rise in interest rates may cause investors to move out of fixed income securities on a large scale, which could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions for the Portfolio. During periods when inflation rates are high or rising, or during periods of low interest rates, the Portfolio may be subject to a greater risk of rising interest rates. Interest rate changes can be sudden and unpredictable and may have unpredictable effects on the markets and the Portfolio’s investment, may result in heightened market volatility, may impact the liquidity of fixed-income securities and of the Portfolio, and may detract from Portfolio performance. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">CREDIT (OR DEFAULT) RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the inability or unwillingness of an issuer or guarantor of a fixed-income security, or a counterparty to a repurchase or other transaction, to meet its principal or interest payments or other financial obligations in a timely manner will adversely affect the value of the Portfolio’s investments and its returns. Changes in an issuer’s financial strength, the market’s perception of an issuer’s creditworthiness, or in the credit rating of the issuer or the security may also affect the value of the Portfolio’s investment in that issuer. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">DEBT EXTENSION RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that when interest rates rise an issuer will exercise its right to pay principal on certain debt securities held by the Portfolio later than expected. This will cause the value of the security to decrease and the Portfolio may lose opportunities to invest in higher yielding securities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">VARIABLE OR FLOATING RATE INSTRUMENTS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that securities with variable or floating rates can be less sensitive to interest rate changes than securities with fixed interest rates, but may decline in value and negatively impact the Portfolio, particularly if changes in prevailing interest rates are more frequent or sudden than the rate changes for the variable or floating rate securities, which only occur periodically. Although variable and floating rate securities are less sensitive to interest rate risk than fixed-rate securities, they are subject to greater liquidity risk, which could impede their value. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INCOME RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio’s ability to distribute income to shareholders depends on the yield available from the Portfolio’s investments. Falling interest rates will cause the Portfolio’s income to decline. Income risk is generally higher for short-term debt securities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">REPURCHASE AGREEMENTS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the counterparty may default on its obligation to repurchase the underlying instruments collateralizing the repurchase agreement, which may cause the Portfolio to lose money. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INVESTMENT COMPANY RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio will be subject to the risks associated with investments in registered investment companies (“Underlying Funds”), such as the possibility that the value of the securities or instruments held by the Underlying Funds could decrease. Investments in Underlying Funds may involve duplication of management fees and certain other expenses, as the Portfolio indirectly bears its proportionate share of any expenses paid by the Underlying </span></div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">Funds in which it invests. NTI may be subject to potential conflicts of interest with respect to investments in affiliated Underlying Funds, which are Underlying Funds managed by NTI or its affiliates, because the fees paid to NTI by some affiliated Underlying Funds may be higher than the fees paid by other Underlying Funds.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">CASH POSITIONS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that maintaining cash positions may negatively affect the Portfolio’s performance and potentially limit investment opportunities as a result of the Portfolio’s uninvested assets. Maintaining cash positions may also subject the Portfolio to increased credit risk exposure to the custodian bank. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">MARKET RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the value of the Portfolio’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Portfolio may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, elevated levels of government debt, changes in interest rates, lack of liquidity in the bond or equity markets or volatility in the equity markets. Market disruptions caused by local or regional events such as financial institution failures, changes in trade regulation or economic sanctions, internal unrest and discord, war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions, the threat or occurrence of a government shutdown, or other events or adverse investor sentiment could have a significant impact on the Portfolio and its investments. During periods of market disruption or other abnormal market conditions, the Portfolio’s exposure to risks described elsewhere in this summary will likely increase. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">MANAGEMENT RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that a strategy used by the Portfolio’s investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">LARGE SHAREHOLDER RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that a large proportion of the interests of the Portfolio may be held by a small number of investors (or a single investor) and the Portfolio may experience adverse effects when certain large shareholders, including funds or accounts over which the Portfolio’s investment adviser or an affiliate of the investment adviser has investment discretion, purchase or redeem large amounts of shares of the Portfolio. Such large shareholder redemptions, which may occur rapidly and unexpectedly, may cause the Portfolio to sell its securities at times it would not otherwise do so, which may negatively impact its liquidity and/or NAV. Such sales may also accelerate the realization of taxable income to shareholders if these sales result in gains, and may also increase transaction costs. In addition, large redemptions could lead to an increase in the Portfolio’s expense ratio due to expenses being allocated over a smaller asset base. Large purchases of the Portfolio’s shares or having a more concentrated shareholder base may also adversely affect the Portfolio’s performance to the extent that the Portfolio is delayed in investing new cash or otherwise maintains a larger cash position than it ordinarily would. </span></div>
You could lose money by investing in the Portfolio.
Although the Portfolio seeks to preserve the value of your investment at $1.00 per share, the Portfolio cannot guarantee it will do so.
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;">An investment in the Portfolio is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, Siebert Williams Shank & Co., LLC or its affiliates, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.</span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;">The Portfolio’s sponsor is not required to reimburse the Portfolio for losses, and you should not expect that the sponsor will provide financial support to the Portfolio at any time, including during periods of market stress.</span></div>
PORTFOLIO PERFORMANCE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio from year to year. Performance shown prior to December 22, 2021, the inception date of Siebert Williams Shank Shares, is that of Shares Class, another class of shares of the Portfolio that is offered in a separate prospectus. Siebert Williams Shank Shares would have substantially similar annual returns because the Shares Class is invested in the same portfolio of securities and the annual returns would differ only to the extent that the classes do not have the same expenses.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">Updated performance information for the Portfolio is available and may be obtained on the Portfolio’s website at https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance or by calling 800‑637‑1380.</div>
The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio from year to year.
The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.
https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance
800‑637‑1380
CALENDAR YEAR TOTAL RETURNS (SIEBERT WILLIAMS SHANK)*
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">* For the periods shown in the bar chart above: </span></div>
<table cellpadding="0" cellspacing="0" style="border-collapse: collapse; font-family: arial; font-size: 8pt; width: 100%; border-spacing: 0px; margin: 0 auto;">
<tr>
<td style="width: 53%;"></td>
<td style="vertical-align: bottom;"></td>
<td style="width: 9%;"></td>
<td style="vertical-align: bottom; width: 3%;"></td>
<td style="width: 29%;"></td> </tr>
<tr style="page-break-inside: avoid; font-family: arial; font-size: 8pt;">
<td style="vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">highest quarterly return</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom; white-space: nowrap;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">1.33%</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;">fourth quarter of 2023</td> </tr>
<tr style="page-break-inside: avoid; font-family: arial; font-size: 8pt;">
<td style="vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">lowest quarterly return</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom; white-space: nowrap;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">0.01%</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;">first quarter of 2022</td> </tr> </table>
highest quarterly return
0.0133
2023-12-31
lowest quarterly return
0.0001
2022-03-31
AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, 2025)
0.0419
0.0312
0.0208
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">The 7‑day yield for Siebert Williams Shank Shares of the Portfolio as of December 31, 2025: 3.68%. For the current 7‑day yield call 800‑637‑1380 or visit https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#priceyield. </span></div>
The 7‑day yield for Siebert Williams Shank Shares of the Portfolio as of December 31, 2025:
0.0368
800‑637‑1380
TREASURY INSTRUMENTS PORTFOLIO
INVESTMENT OBJECTIVE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio seeks to maximize current income to the extent consistent with the preservation of capital and maintenance of liquidity by investing its net assets, under normal conditions, exclusively in U.S. Treasury securities.</div>
FEES AND EXPENSES OF THE PORTFOLIO
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">This table describes the fees and expenses that you may pay if you buy, hold and sell Siebert Williams Shank Shares of the Portfolio. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Siebert Williams Shank Shares, which are not reflected in the tables or the examples below.</div>
Shareholder Fees (fees paid directly from your investment)
0
Annual Portfolio Operating Expenses (expenses that you pay each year asa percentage of the value of your investment)
0.0016
0.0002
0.0002
0
0.0000
0.0018
0.0000
0.0018
“Other Expenses” are based on estimated amounts for the current fiscal year.
April 1, 2027
EXAMPLE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The following Example is intended to help you compare the cost of investing in Siebert Williams Shank Shares of the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Portfolio’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:</div>
18
58
101
230
PRINCIPAL INVESTMENT STRATEGIES
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 10pt; font-family: times new roman;">The Portfolio seeks to achieve its objective by investing, under normal circumstances, its total assets exclusively in:</div>
<table cellpadding="0" cellspacing="0" style="border-collapse: collapse; font-family: times new roman; font-size: 9.5pt; border-spacing: 0px; width: 100%;">
<tr style="page-break-inside: avoid;">
<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">Cash; and</div> </td> </tr> </table>
<table cellpadding="0" cellspacing="0" style="border-collapse: collapse; font-family: times new roman; font-size: 9.5pt; border-spacing: 0px; width: 100%;">
<tr style="page-break-inside: avoid;">
<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">Short-term bills, notes and other obligations issued or guaranteed by the U.S. Treasury (“Treasury Obligations”).</div> </td> </tr> </table> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio, under normal circumstances, will invest at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in Treasury Obligations. Repurchase agreements are agreements in which the Portfolio agrees to purchase portfolio securities from financial institutions subject to the seller’s agreement to repurchase them at a mutually agreed upon date and price.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio operates as a “government money market fund” under Rule 2a‑7 of the Investment Company Act of 1940, as amended. As a “government money market fund” under Rule 2a‑7, the Portfolio (1) is permitted to use the amortized cost method of valuation to seek to maintain a stable net asset value (“NAV”) of $1.00 share price, and (2) is not required to impose a liquidity fee on Portfolio redemptions that might apply to other types of money market funds. The Portfolio may invest in shares of other government money market funds.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Securities and Exchange Commission (“SEC”) imposes strict requirements on the investment quality, maturity, diversification and liquidity of the Portfolio’s investments. Accordingly, the Portfolio invests in U.S. dollar-denominated securities with a remaining maturity of no more than 397 days (with certain exceptions permitted by applicable regulations). The Portfolio maintains a dollar-weighted average portfolio maturity of no more than 60 calendar days, and a dollar-weighted average portfolio maturity as determined without</div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">exceptions regarding certain interest rate adjustments under Rule 2a‑7 of no more than 120 calendar days. The Portfolio will limit its investments to “eligible securities,” as defined by applicable regulations, at the time of acquisition (e.g., government securities, shares of other money market funds, and securities that present minimal credit risks as determined by NTI, pursuant to guidelines approved by the Portfolio’s Board of Trustees). The Portfolio may invest in variable and floating rate instruments. The Portfolio’s investment adviser may consider, among other things, credit and interest rate risks as well as general market conditions when deciding whether to buy or sell investments for the Portfolio. The Portfolio will generally hold a portion of its assets in cash to accommodate anticipated redemptions.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">STABLE NAV RISK</span></span> is the risk that the Portfolio will not be able to maintain a NAV per share of $1.00 at all times. A significant enough market disruption or drop in market prices of securities held by the Portfolio, especially at a time when the Portfolio needs to sell securities to meet shareholder redemption requests, could cause the value of the Portfolio’s shares to decrease to a price less than $1.00 per share. If the Portfolio fails to maintain a stable NAV (or if there is a perceived threat of such a failure) the Portfolio could be subject to increased redemption activity, which could adversely affect its NAV.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">INTEREST RATE RISK</span></span> is the risk that during periods of rising interest rates, the market value of the Portfolio’s securities will tend to be lower than prevailing market rates and in periods of falling interest rates, the market value of the Portfolio’s securities will tend to be higher. The Portfolio’s yield will vary as short-term securities in its portfolio mature and the proceeds are reinvested in securities with different interest rates. In general, securities with longer maturities or durations are more sensitive to interest rate changes. A general rise in interest rates may cause investors to move out of fixed income securities on a large scale, which could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions for the Portfolio. During periods when inflation rates are high or rising, or during periods of low interest rates, the Portfolio may be subject to a greater risk of rising interest rates. Interest rate changes can be sudden and unpredictable and may have unpredictable effects on the markets and the Portfolio’s investment, may result in heightened market volatility, may impact the liquidity of fixed-income securities and of the Portfolio, and may detract from Portfolio performance.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">CREDIT (OR DEFAULT) RISK</span></span> is the risk that the inability or unwillingness of an issuer or guarantor of a fixed-income security, or a counterparty to a repurchase or other transaction, to meet its principal or interest payments or other financial obligations in a timely manner will adversely affect the value of the Portfolio’s investments and its returns. Changes in an issuer’s financial strength, the market’s perception of an issuer’s creditworthiness, or in the credit rating of the issuer or the security may also affect the value of the Portfolio’s investment in that issuer.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">DEBT EXTENSION RISK</span></span> is the risk that when interest rates rise an issuer will exercise its right to pay principal on certain debt securities held by the Portfolio later than expected. This will cause the value of the security to decrease and the Portfolio may lose opportunities to invest in higher yielding securities.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">VARIABLE OR FLOATING RATE INSTRUMENTS RISK</span></span> is the risk that securities with variable or floating rates can be less sensitive to interest rate changes than securities with fixed interest rates, but may decline in value and negatively impact the Portfolio, particularly if changes in prevailing interest rates are more frequent or sudden than the rate changes for the variable or floating rate securities, which only occur periodically. Although variable and floating rate securities are less sensitive to interest rate risk than fixed-rate securities, they are subject to greater liquidity risk, which could impede their value.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">INCOME RISK</span></span> is the risk that the Portfolio’s ability to distribute income to shareholders depends on the yield available from the Portfolio’s investments. Falling interest rates will cause the Portfolio’s income to decline. Income risk is generally higher for short-term debt securities.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">LARGE SHAREHOLDER RISK</span></span> is the risk that a large proportion of the interests of the Portfolio may be held by a small number of investors (or a single investor) and the Portfolio may experience adverse effects when certain large shareholders, including funds or accounts over which the Portfolio’s investment adviser or an affiliate of the investment adviser has investment discretion, purchase or redeem large amounts of shares of the Portfolio. Such large shareholder redemptions, which may occur rapidly and unexpectedly, may cause the Portfolio to sell its securities at times it would not otherwise do so, which may negatively impact its liquidity and/or NAV. Such sales may also accelerate</div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">the realization of taxable income to shareholders if these sales result in gains, and may also increase transaction costs. In addition, large redemptions could lead to an increase in the Portfolio’s expense ratio due to expenses being allocated over a smaller asset base. Large purchases of the Portfolio’s shares or having a more concentrated shareholder base may also adversely affect the Portfolio’s performance to the extent that the Portfolio is delayed in investing new cash or otherwise maintains a larger cash position than it ordinarily would.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INVESTMENT COMPANY RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio will be subject to the risks associated with investments in registered investment companies (“Underlying Funds”), such as the possibility that the value of the securities or instruments held by the Underlying Funds could decrease. Investments in Underlying Funds may involve duplication of management fees and certain other expenses, as the Portfolio indirectly bears its proportionate share of any expenses paid by the Underlying Funds in which it invests. NTI may be subject to potential conflicts of interest with respect to investments in affiliated Underlying Funds, which are Underlying Funds managed by NTI or its affiliates, because the fees paid to NTI by some affiliated Underlying Funds may be higher than the fees paid by other Underlying Funds. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">MARKET RISK</span></span> is the risk that the value of the Portfolio’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Portfolio may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, elevated levels of government debt, changes in interest rates, lack of liquidity in the bond or equity markets or volatility in the equity markets. Market disruptions caused by local or regional events such as financial institution failures, changes in trade regulation or economic sanctions, internal unrest and discord, war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions, the threat or occurrence of a government shutdown, or other events or adverse investor sentiment could have a significant impact on the Portfolio and its investments. During periods of market disruption or other abnormal market conditions, the Portfolio’s exposure to risks described elsewhere in this summary will likely increase.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">CASH POSITIONS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that maintaining cash positions may negatively affect the Portfolio’s performance and potentially limit investment opportunities as a result of the Portfolio’s uninvested assets. Maintaining cash positions may also subject the Portfolio to increased credit risk exposure to the custodian bank . </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;"><span style="font-family: arial; font-size: 7.5pt;">MANAGEMENT RISK</span></span> is the risk that a strategy used by the Portfolio’s investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results.</div>
You could lose money by investing in the Portfolio.
Although the Portfolio seeks to preserve the value of your investment at $1.00 per share, the Portfolio cannot guarantee it will do so.
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman; font-weight: bold;">An investment in the Portfolio is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, Siebert Williams Shank & Co., LLC or its affiliates, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman; font-weight: bold;">The Portfolio’s sponsor is not required to reimburse the Portfolio for losses, and you should not expect that the sponsor will provide financial support to the Portfolio at any time, including during periods of market stress.</div>
PORTFOLIO PERFORMANCE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio from year to year. Performance shown prior to October 24, 2025, the inception date of Siebert Williams Shank Shares, is that of Premier Class, another class of shares of the Portfolio that is offered in a separate prospectus. Siebert Williams Shank Shares would have substantially similar annual returns because the Premier Class is invested in the same portfolio of securities and the annual returns would differ only to the extent that the classes do not have the same expenses.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">Updated performance information for the Portfolio is available and may be obtained on the Portfolio’s website at https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance or by calling 800‑637‑1380.</div>
The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio from year to year.
The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.
https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance
800‑637‑1380
CALENDAR YEAR TOTAL RETURNS (SIEBERT WILLIAMS SHANK)*
<div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">* For the periods shown in the bar chart above: </span></div>
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<tr>
<td style="width: 53%;"></td>
<td style="vertical-align: bottom;"></td>
<td style="width: 9%;"></td>
<td style="vertical-align: bottom; width: 3%;"></td>
<td style="width: 29%;"></td> </tr>
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<td style="vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">highest quarterly return</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom; white-space: nowrap; text-align: center;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial; text-align: center;">1.06%</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;">first quarter of 2025</td> </tr>
<tr style="page-break-inside: avoid; font-family: arial; font-size: 8pt;">
<td style="vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">lowest quarterly return</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom; white-space: nowrap; text-align: center;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial; text-align: center;">0.98%</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;">fourth quarter of 2025</td> </tr> </table>
highest quarterly return
0.0106
2025-03-31
lowest quarterly return
0.0098
2025-12-31
AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, 2025)
2025-10-24
0.0421
0.0449
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">The 7‑day yield for Siebert Williams Shank Shares of the Portfolio as of December 31, 2025: 3.75%. For the current 7‑day yield call 800‑637‑1380 or visit https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#priceyield. </span></div>
The 7‑day yield for Siebert Williams Shank Shares of the Portfolio as of December 31, 2025:
0.0375
800‑637‑1380
U.S. GOVERNMENT SELECT PORTFOLIO
INVESTMENT OBJECTIVE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio seeks to maximize current income to the extent consistent with the preservation of capital and maintenance of liquidity by investing exclusively in high quality money market instruments.</div>
FEES AND EXPENSES OF THE PORTFOLIO
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">This table describes the fees and expenses that you may pay if you buy, hold, and sell Siebert Williams Shank Shares of the Portfolio. You may be required to pay commissions and/or other forms of compensation to a financial intermediary for transactions in Siebert Williams Shank Shares, which are not reflected in the tables or the examples below.</div>
Shareholder Fees (fees paid directly from your investment)
0
Annual Portfolio Operating Expenses (expenses that you pay each year asa percentage of the value of your investment)
0.0018
0.0003
0.0002
0
0.0001
0.0021
-0.0001
0.0020
April 1, 2027
EXAMPLE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The following Example is intended to help you compare the cost of investing in Siebert Williams Shank Shares of the Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Portfolio’s operating expenses remain the same (taking into account the expense reimbursement arrangement for one year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:</div>
20
67
117
267
PRINCIPAL INVESTMENT STRATEGIES
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio seeks to achieve its objective by investing, under normal circumstances, substantially all (and at least 99.5%) of its total assets in cash, securities issued or guaranteed as to principal or interest by the U.S. government, its agencies, instrumentalities, or sponsored enterprises; and repurchase agreements that are fully collateralized by cash or government securities. Subject to the foregoing 99.5% investment strategy requirement, under normal circumstances, the Portfolio will seek to invest at least 50% of its net assets in the following securities that pay interest that generally is exempt from state income taxation:</div>
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<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">U.S. Treasury bills;</div> </td> </tr> </table>
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<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">U.S. Treasury notes;</div> </td> </tr> </table>
<table cellpadding="0" cellspacing="0" style="border-collapse: collapse; font-family: times new roman; font-size: 9.5pt; border-spacing: 0px; width: 100%;">
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<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">U.S. Treasury STRIPS;</div> </td> </tr> </table>
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<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">securities issued by the Federal Home Loan Bank (FHLB);</div> </td> </tr> </table>
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<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">securities issued by the Federal Farm Credit Bank (FFCB); and</div> </td> </tr> </table>
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<td style="width: 1%; vertical-align: top; text-align: left;">∎</td>
<td style="width: 1%; vertical-align: top;"> </td>
<td style="vertical-align: top; text-align: left;"> <div style="margin-top: 0pt; margin-bottom: 0pt; font-family: times new roman; font-size: 9.5pt; text-align: left;">securities issued by the Tennessee Valley Authority.</div> </td> </tr> </table> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio, under normal circumstances, will invest at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in U.S. government securities and repurchase agreements collateralized solely by U.S. government securities. Repurchase agreements are agreements in which the Portfolio agrees to purchase portfolio securities from financial institutions subject to the seller’s agreement to repurchase them at a mutually agreed upon date and price.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio operates as a “government money market fund” under Rule 2a‑7 of the Investment Company Act of 1940, as amended. As a “government money market fund” under Rule 2a‑7, the Portfolio (1) is permitted to use the amortized cost method of valuation to seek to maintain a stable net asset value (“NAV”) of $1.00 share price, and (2) is not required to impose a liquidity fee on Portfolio redemptions that might</div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">apply to other types of money market funds. The Portfolio may invest in shares of other government money market funds.</div> <div style="margin-top: 4pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Securities and Exchange Commission (“SEC”) imposes strict requirements on the investment quality, maturity, diversification and liquidity of the Portfolio’s investments. Accordingly, the Portfolio invests in U.S. dollar-denominated securities with a remaining maturity of no more than 397 days (with certain exceptions permitted by applicable regulations). The Portfolio maintains a dollar-weighted average portfolio maturity of no more than 60 calendar days, and a dollar-weighted average portfolio maturity as determined without exceptions regarding certain interest rate adjustments under Rule 2a‑7 of no more than 120 calendar days. The Portfolio will limit its investments to “eligible securities,” as defined by applicable regulations, at the time of acquisition (e.g., government securities, shares of other money market funds, and securities that present minimal credit risks as determined by NTI, pursuant to guidelines approved by the Portfolio’s Board of Trustees). The Portfolio may invest in variable and floating rate instruments. The Portfolio’s investment adviser may consider, among other things, credit, interest rate and prepayment risks as well as general market conditions when deciding whether to buy or sell investments for the Portfolio. The Portfolio will generally hold a portion of its assets in cash to accommodate anticipated redemptions.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">STABLE NAV RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio will not be able to maintain a NAV per share of $1.00 at all times. A significant enough market disruption or drop in market prices of securities held by the Portfolio, especially at a time when the Portfolio needs to sell securities to meet shareholder redemption requests, could cause the value of the Portfolio’s shares to decrease to a price less than $1.00 per share. If the Portfolio fails to maintain a stable NAV (or if there is a perceived threat of such a failure) the Portfolio could be subject to increased redemption activity, which could adversely affect its NAV. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INTEREST RATE RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that during periods of rising interest rates, the market value of a Portfolio’s securities will tend to be lower than prevailing market rates and in periods of falling interest rates, the market value of a Portfolio’s securities will tend to be higher. A Portfolio’s yield will vary as short-term securities in its portfolio mature and the proceeds are reinvested in securities with different interest rates. In general, securities with longer maturities or durations are more sensitive to interest rate changes. A general rise in interest rates may cause investors to move out of fixed income securities on a large scale, which could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions for the Portfolio. During periods when inflation rates are high or rising, or during periods of low interest rates, the Portfolio may be subject to a greater risk of rising interest rates. Interest rate changes can be sudden and unpredictable and may have unpredictable effects on the markets and the Portfolio’s investment, may result in heightened market volatility, may impact the liquidity of fixed-income securities and of the Portfolio, and may detract from Portfolio performance. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">CREDIT (OR DEFAULT) RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the inability or unwillingness of an issuer or guarantor of a fixed-income security, or a counterparty to a repurchase or other transaction, to meet its principal or interest payments or other financial obligations in a timely manner will adversely affect the value of the Portfolio’s investments and its returns. Changes in an issuer’s financial strength, the market’s perception of an issuer’s creditworthiness, or in the credit rating of the issuer or the security may also affect the value of the Portfolio’s investment in that issuer. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">DEBT EXTENSION RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that when interest rates rise an issuer will exercise its right to pay principal on certain debt securities held by the Portfolio later than expected. This will cause the value of the security to decrease and the Portfolio may lose opportunities to invest in higher yielding securities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">PREPAYMENT (OR CALL) RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that an issuer could exercise its right to pay principal on callable debt securities held by the Portfolio earlier than expected. Issuers may be more likely to prepay their securities if interest rates fall. If this happens, the Portfolio will not benefit from the rise in the market price of the securities that normally accompanies a decline in interest rates, and will be forced to reinvest prepayment proceeds in lower yielding securities, which may reduce the Portfolio’s returns. The Portfolio may also lose any premium it paid to purchase the securities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">VARIABLE OR FLOATING RATE INSTRUMENTS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that securities with variable or floating rates can be less sensitive to interest rate changes than securities with fixed interest rates, but may decline in value and negatively impact the Portfolio, particularly if changes in prevailing interest rates are more frequent or sudden than the rate changes for the variable or floating rate securities, which only occur periodically. Although </span></div> <div style="margin-top: 0pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">variable and floating rate securities are less sensitive to interest rate risk than fixed-rate securities, they are subject to greater liquidity risk, which could impede their value.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INCOME RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio’s ability to distribute income to shareholders depends on the yield available from the Portfolio’s investments. Falling interest rates will cause the Portfolio’s income to decline. Income risk is generally higher for short-term debt securities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">U.S. GOVERNMENT SECURITIES RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the U.S. government will not provide financial support to its agencies, instrumentalities or sponsored enterprises if it is not obligated to do so by law. Certain U.S. government securities purchased by the Portfolio are neither issued nor guaranteed by the U.S. Treasury and, therefore, may not be backed by the full faith and credit of the United States. The maximum potential liability of the issuers of some U.S. government securities may greatly exceed their current resources, including any legal right to support from the U.S. Treasury. It is possible that the issuers of such securities will not have the funds to meet their payment obligations in the future. U.S. government securities include zero coupon securities, which tend to be subject to greater market risk than interest-paying securities of similar maturities. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">REPURCHASE AGREEMENTS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the counterparty may default on its obligation to repurchase the underlying instruments collateralizing the repurchase agreement, which may cause the Portfolio to lose money. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">INVESTMENT COMPANY RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the Portfolio will be subject to the risks associated with investments in registered investment companies (“Underlying Funds”), such as the possibility that the value of the securities or instruments held by the Underlying Funds could decrease. Investments in Underlying Funds may involve duplication of management fees and certain other expenses, as the Portfolio indirectly bears its proportionate share of any expenses paid by the Underlying Funds in which it invests. NTI may be subject to potential conflicts of interest with respect to investments in affiliated Underlying Funds, which are Underlying Funds managed by NTI or its affiliates, because the fees paid to NTI by some affiliated Underlying Funds may be higher than the fees paid by other Underlying Funds. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">MARKET RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that the value of the Portfolio’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Portfolio may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, elevated levels of government debt, changes in interest rates, lack of liquidity in the bond or equity markets or volatility in the equity markets. </span></div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">Market disruptions caused by local or regional events such as financial institution failures, changes in trade regulation or economic sanctions, internal unrest and discord, war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions, the threat or occurrence of a government shutdown, or other events or adverse investor sentiment could have a significant impact on the Portfolio and its investments. During periods of market disruption or other abnormal market conditions, the Portfolio’s exposure to risks described elsewhere in this summary will likely increase.</div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">CASH POSITIONS RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that maintaining cash positions may negatively affect the Portfolio’s performance and potentially limit investment opportunities as a result of the Portfolio’s uninvested assets. Maintaining cash positions may also subject the Portfolio to increased credit risk exposure to the custodian bank . </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">MANAGEMENT RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that a strategy used by the Portfolio’s investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results. </span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-family: arial; font-size: 7.5pt;"><span style="font-weight: bold;">LARGE SHAREHOLDER RISK</span></span><span style="font-family: times new roman; font-size: 9.5pt;"> is the risk that a large proportion of the interests of the Portfolio may be held by a small number of investors (or a single investor) and the Portfolio may experience adverse effects when certain large shareholders, including funds or accounts over which the Portfolio’s investment adviser or an affiliate of the investment adviser has investment discretion, purchase or redeem large amounts of shares of the Portfolio. Such large shareholder redemptions, which may occur rapidly and unexpectedly, may cause the Portfolio to sell its securities at times it would not otherwise do so, which may negatively impact its liquidity and/or NAV. Such sales may also accelerate the realization of taxable income to shareholders if these sales result in gains, and may also increase transaction costs. In addition, large redemptions could lead to an increase in the Portfolio’s expense ratio due to expenses being allocated over a smaller asset base. Large purchases of the Portfolio’s shares or having a more concentrated shareholder base may also adversely affect the Portfolio’s performance to the extent that the Portfolio is delayed in investing new cash or otherwise maintains a larger cash position than it ordinarily would. </span></div>
You could lose money by investing in the Portfolio.
Although the Portfolio seeks to preserve the value of your investment at $1.00 per share, the Portfolio cannot guarantee it will do so.
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;">An investment in the Portfolio is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance</span> <span style="font-weight: bold;">Corporation, any other government agency, Siebert Williams Shank & Co., LLC or its affiliates, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.</span></div>
<div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;"><span style="font-weight: bold;">The Portfolio’s sponsor is not required to reimburse the Portfolio for losses, and you should not expect that the sponsor will provide financial support to the Portfolio at any time, including during periods of market stress.</span></div>
PORTFOLIO PERFORMANCE
<div style="margin-top: 14pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio from year to year.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.</div> <div style="margin-top: 6pt; margin-bottom: 0pt; font-size: 9.5pt; font-family: times new roman;">Updated performance information for the Portfolio is available and may be obtained on the Portfolio’s website at https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance or by calling 800‑637‑1380.</div>
The bar chart and table that follow provide an indication of the risks of investing in the Portfolio by showing changes in the performance of the Portfolio from year to year.
The Portfolio’s past performance is not necessarily an indication of how the Portfolio will perform in the future.
https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#performance
800‑637‑1380
CALENDAR YEAR TOTAL RETURNS (SIEBERT WILLIAMS SHANK)*
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">* For the periods shown in the bar chart above: </span></div>
<table cellpadding="0" cellspacing="0" style="border-collapse: collapse; font-family: arial; font-size: 8pt; width: 100%; border-spacing: 0px; margin: 0 auto;">
<tr>
<td style="width: 36%;"></td>
<td style="vertical-align: bottom;"></td>
<td style="width: 27%;"></td>
<td style="vertical-align: bottom; width: 3%;"></td>
<td style="width: 28%;"></td> </tr>
<tr style="page-break-inside: avoid; font-family: arial; font-size: 8pt;">
<td style="vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">highest quarterly return</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom; white-space: nowrap; text-align: center;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial; text-align: center;">1.32%</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;">fourth quarter of 2023</td> </tr>
<tr style="page-break-inside: avoid; font-family: arial; font-size: 8pt;">
<td style="vertical-align: top;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial;">lowest quarterly return</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom; white-space: nowrap; text-align: center;"> <div style="margin-top: 0pt; margin-bottom: 0pt; margin-left: 0.50em; font-size: 8pt; font-family: arial; text-align: center;">0.00%</div> </td>
<td style="vertical-align: bottom;"> </td>
<td style="vertical-align: bottom;">fourth quarter of 2020</td> </tr> </table>
highest quarterly return
0.0132
2023-12-31
lowest quarterly return
0.0000
2020-12-31
AVERAGE ANNUAL TOTAL RETURNS (For the periods ended December 31, 2025)
0.0420
0.0311
0.0206
<div style="margin-top: 12pt; margin-bottom: 0pt; font-size: 7.5pt; font-family: arial;"><span style="font-style: italic;">The 7‑day yield for Siebert Williams Shank Shares of the Portfolio as of December 31, 2025: 3.66%. For the current 7‑day yield call 800‑637‑1380 or visit https://ntam.northerntrust.com/united-states/institutional/strategies/cash/northern-institutional-funds#priceyield. </span></div>
The 7‑day yield for Siebert Williams Shank Shares of the Portfolio as of December 31, 2025:
0.0366
800‑637‑1380
Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Portfolio so that after such reimbursement the Total Annual Fund Operating Expenses of the Portfolio (excluding (i) acquired fund fees and expenses; (ii) service fees; (iii) the compensation paid to each Independent Trustee of the Trust; (iv) expenses of third party consultants engaged by the Board of Trustees; (v) membership dues paid to the Investment Company Institute and Mutual Fund Directors Forum; (vi) expenses in connection with the negotiation and renewal of the revolving credit facility; and (vii) extraordinary expenses and interest) do not exceed 0.25%. This contractual limitation may not be terminated before April 1, 2027 without the approval of the Board of Trustees.
Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Portfolio so that after such reimbursement the Total Annual Fund Operating Expenses of the Portfolio (excluding (i) acquired fund fees and expenses; (ii) service fees; (iii) the compensation paid to each Independent Trustee of the Trust; (iv) expenses of third party consultants engaged by the Board of Trustees; (v) membership dues paid to the Investment Company Institute and Mutual Fund Directors Forum; (vi) expenses in connection with the negotiation and renewal of the revolving credit facility; and (vii) extraordinary expenses and interest) do not exceed 0.20%. This contractual limitation may not be terminated before April 1, 2027 without the approval of the Board of Trustees.
The Total Annual Portfolio Operating Expenses After Expense Reimbursement do not correlate to the Portfolio’s ratio of average net assets to expenses, net of waivers, reimbursements and credits, included in the Portfolio’s Financial Highlights in the Portfolio’s complete Prospectus, which reflect voluntary expense reimbursements made by NTI to the Portfolio. Such voluntary reimbursements may be discontinued at any time.
“Other Expenses” are based on estimated amounts for the current fiscal year.
“Other Expenses” are based on estimated amounts for the current fiscal year.
Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Portfolio so that after such reimbursement the Total Annual Fund Operating Expenses of the Portfolio (excluding (i) acquired fund fees and expenses; (ii) service fees; (iii) the compensation paid to each Independent Trustee of the Trust; (iv) expenses of third party consultants engaged by the Board of Trustees; (v) membership dues paid to the Investment Company Institute and Mutual Fund Directors Forum; (vi) expenses in connection with the negotiation and renewal of the revolving credit facility; and (vii) extraordinary expenses and interest) do not exceed 0.20%. This contractual limitation may not be terminated before April 1, 2027 without the approval of the Board of Trustees.
The Total Annual Portfolio Operating Expenses After Expense Reimbursement do not correlate to the Portfolio’s ratio of average net assets to expenses, net of waivers, reimbursements and credits, included in the Portfolio’s Financial Highlights in the Portfolio’s complete Prospectus, which reflect voluntary expense reimbursements made by NTI to the Portfolio. Such voluntary reimbursements may be discontinued at any time.
Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Portfolio so that after such reimbursement the Total Annual Fund Operating Expenses of the Portfolio (excluding (i) acquired fund fees and expenses; (ii) service fees; (iii) the compensation paid to each Independent Trustee of the Trust; (iv) expenses of third party consultants engaged by the Board of Trustees; (v) membership dues paid to the Investment Company Institute and Mutual Fund Directors Forum; (vi) expenses in connection with the negotiation and renewal of the revolving credit facility; and (vii) extraordinary expenses and interest) do not exceed 0.15%. This contractual limitation may not be terminated before April 1, 2027, without the approval of the Board of Trustees.
“Other Expenses” are based on estimated amounts for the current fiscal year.
Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Portfolio so that after such reimbursement the Total Annual Fund Operating Expenses of the Portfolio (excluding (i) acquired fund fees and expenses; (ii) service fees; (iii) the compensation paid to each Independent Trustee of the Trust; (iv) expenses of third party consultants engaged by the Board of Trustees; (v) membership dues paid to the Investment Company Institute and Mutual Fund Directors Forum; (vi) expenses in connection with the negotiation and renewal of the revolving credit facility; and (vii) extraordinary expenses and interest) do not exceed 0.18%. This contractual limitation may not be terminated before April 1, 2027, without the approval of the Board of Trustees.
The Total Annual Portfolio Operating Expenses After Expense Reimbursement do not correlate to the Portfolio’s ratio of average net assets to expenses, net of waivers, reimbursements and credits, included in the Portfolio’s Financial Highlights in the Portfolio’s complete Prospectus, which reflect voluntary expense reimbursements made by NTI to the Portfolio. Such voluntary reimbursements may be discontinued at any time.
“Other Expenses” are based on estimated amounts for the current fiscal year.
Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Portfolio so that after such reimbursement the Total Annual Fund Operating Expenses of the Portfolio (excluding (i) acquired fund fees and expenses; (ii) service fees; (iii) the compensation paid to each Independent Trustee of the Trust; (iv) expenses of third party consultants engaged by the Board of Trustees; (v) membership dues paid to the Investment Company Institute and Mutual Fund Directors Forum; (vi) expenses in connection with the negotiation and renewal of the revolving credit facility; and (vii) extraordinary expenses and interest) do not exceed 0.20%. This contractual limitation may not be terminated before April 1, 2027, without the approval of the Board of Trustees.
Inception Date of Premier Shares is June 11, 2024. Performance shown prior to October 24, 2025, the inception date of Siebert Williams Shank Shares, is that of Premier Shares..
The Total Annual Portfolio Operating Expenses After Expense Reimbursement do not correlate to the Portfolio’s ratio of average net assets to expenses, net of waivers, reimbursements and credits included in the Portfolio’s Financial Highlights in the Portfolio’s complete Prospectus, which reflect voluntary expense reimbursements made by NTI to the Portfolio. Such voluntary reimbursements may be discontinued at any time.
Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Portfolio so that after such reimbursement the Total Annual Fund Operating Expenses of the Portfolio (excluding (i) acquired fund fees and expenses; (ii) service fees; (iii) the compensation paid to each Independent Trustee of the Trust; (iv) expenses of third party consultants engaged by the Board of Trustees; (v) membership dues paid to the Investment Company Institute and Mutual Fund Directors Forum; (vi) expenses in connection with the negotiation and renewal of the revolving credit facility; and (vii) extraordinary expenses and interest) do not exceed 0.15%. The “Total Annual Portfolio Operating Expenses After Expense Reimbursement” may be higher than the contractual limitation as a result of certain Portfolio expenses, including but not limited to service fees, that are not reimbursed. This contractual limitation may not be terminated before April 1, 2027 without the approval of the Board of Trustees.
Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Portfolio so that after such reimbursement the Total Annual Fund Operating Expenses of the Portfolio (excluding (i) acquired fund fees and expenses; (ii) service fees; (iii) the compensation paid to each Independent Trustee of the Trust; (iv) expenses of third party consultants engaged by the Board of Trustees; (v) membership dues paid to the Investment Company Institute and Mutual Fund Directors Forum; (vi) expenses in connection with the negotiation and renewal of the revolving credit facility; and (vii) extraordinary expenses and interest) do not exceed 0.18%. This contractual limitation may not be terminated before April 1, 2027 without the approval of the Board of Trustees.
The Total Annual Portfolio Operating Expenses After Expense Reimbursement do not correlate to the Portfolio’s ratio of average net assets to expenses, net of waivers, reimbursements and credits, included in the Portfolio’s Financial Highlights in the Portfolio’s complete Prospectus, which reflect voluntary expense reimbursements made by NTI to the Portfolio. Such voluntary reimbursements may be discontinued at any time.
“Other Expenses” are based on estimated amounts for the current fiscal year.
Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Portfolio so that after such reimbursement the Total Annual Fund Operating Expenses of the Portfolio (excluding (i) acquired fund fees and expenses; (ii) service fees; (iii) the compensation paid to each Independent Trustee of the Trust; (iv) expenses of third party consultants engaged by the Board of Trustees; (v) membership dues paid to the Investment Company Institute and Mutual Fund Directors Forum; (vi) expenses in connection with the negotiation and renewal of the revolving credit facility; and (vii) extraordinary expenses and interest) do not exceed 0.18%. This contractual limitation may not be terminated before April 1, 2027 without the approval of the Board of Trustees.
The Total Annual Portfolio Operating Expenses After Expense Reimbursement do not correlate to the Portfolio’s ratio of average net assets to expenses, net of waivers, reimbursements and credits, included in the Portfolio’s Financial Highlights in the Portfolio’s complete Prospectus, which reflect voluntary expense reimbursements made by NTI to the Portfolio. Such voluntary reimbursements may be discontinued at any time.
Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Portfolio so that after such reimbursement the Total Annual Fund Operating Expenses of the Portfolio (excluding (i) acquired fund fees and expenses; (ii) service fees; (iii) the compensation paid to each Independent Trustee of the Trust; (iv) expenses of third party consultants engaged by the Board of Trustees; (v) membership dues paid to the Investment Company Institute and Mutual Fund Directors Forum; (vi) expenses in connection with the negotiation and renewal of the revolving credit facility; and (vii) extraordinary expenses and interest) do not exceed 0.15%. This contractual limitation may not be terminated before April 1, 2027 without the approval of the Board of Trustees.
Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Portfolio so that after such reimbursement the Total Annual Fund Operating Expenses of the Portfolio (excluding (i) acquired fund fees and expenses; (ii) service fees; (iii) the compensation paid to each Independent Trustee of the Trust; (iv) expenses of third party consultants engaged by the Board of Trustees; (v) membership dues paid to the Investment Company Institute and Mutual Fund Directors Forum; (vi) expenses in connection with the negotiation and renewal of the revolving credit facility; and (vii) extraordinary expenses and interest) do not exceed 0.25%. This contractual limitation may not be terminated before April 1, 2027 without the approval of the Board of Trustees.