UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED

MANAGEMENT INVESTMENT COMPANIES

Investment Company Act file number 811-06740

Legg Mason Partners Institutional Trust

(Exact name of registrant as specified in charter)

620 Eighth Avenue, 47^th Floor, New York, NY 10018

(Address of principal executive offices) (Zip code)

Marc A. De Oliveira

Franklin Templeton

100 First Stamford Place

Stamford, CT 06902

(Name and address of agent for service)

Registrant’s telephone number, including area code: 877-6LM-FUND/656-3863

Date of fiscal year end: August 31

Date of reporting period: February 29, 2024

The Semi-Annual Report to Stockholders is filed herewith.

WESTERN ASSET

PREMIER INSTITUTIONAL

U.S. TREASURY RESERVES

Fund objective

The Fund’s investment objective is to provide shareholders with liquidity and as high a level of current income from U.S. government obligations as is consistent with preservation of capital.

Letter from the president

Dear Shareholder,

We are pleased to provide the semi-annual report of Western Asset Premier Institutional U.S. Treasury Reserves for the six-month reporting period ended February 29, 2024. Please read on for Fund performance information during the Fund’s reporting period.

As always, we remain committed to providing you with excellent service and a full spectrum of investment choices. We also remain committed to supplementing the support you receive from your financial advisor. One way we accomplish this is through our website, www.franklintempleton.com. Here you can gain immediate access to market and investment information, including:

We look forward to helping you meet your financial goals.

Sincerely,

Jane Trust, CFA

President and Chief Executive Officer

March 28, 2024

Performance review

As of February 29, 2024, the seven-day current yield for Capital Shares of Western Asset Premier Institutional U.S. Treasury Reserves was 5.26% and the seven-day effective yield, which reflects compounding, was 5.40%.¹

The Fund does not invest directly in securities but instead invests all of its investable assets in an underlying mutual fund, U.S. Treasury Reserves Portfolio (the “Portfolio”), which has the same investment objective and strategies, and substantially the same policies as the Fund. Unless otherwise indicated, references to the Fund include the underlying mutual fund, the Portfolio.

The performance shown represents past performance. Past performance is no guarantee of future results and current performance may be higher or lower than the performance shown above. Yields will fluctuate. To obtain performance data current to the most recent month-end, please visit our website at www.franklintempleton.com.

As of February 29, 2024, absent fee waivers and/or expense reimbursements, the seven-day current yield and the seven-day effective yield for Capital Shares would have been 4.99% and 5.12%, respectively; and the seven-day current yield and the seven-day effective yield for Premium Shares would have been 4.98% and 5.11%, respectively.

The manager has voluntarily undertaken to limit Fund expenses. Such expense limitations may fluctuate daily and are voluntary and temporary and may be terminated by the manager at any time without notice.

You could lose money by investing in the Fund. Although the Fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. An investment in the Fund is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The Fund’s sponsor is not required to reimburse the Fund for losses, and you should not expect that the sponsor will provide financial support to the Fund at any time, including during periods of market stress.

Performance review (cont’d)

As always, thank you for your confidence in our stewardship of your assets.

Sincerely,

Jane Trust, CFA

President and Chief Executive Officer

March 28, 2024

RISKS: You could lose money by investing in the Fund. Although the Fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. An investment in the Fund is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The Fund’s sponsor is not required to reimburse the Fund for losses, and you should not expect that the sponsor will provide financial support to the Fund at any time, including during periods of market stress. During periods of market stress, there could be significant redemptions from money market funds in general, potentially driving the market prices of money market instruments down and adversely affecting market liquidity. Although the Fund invests in U.S. government obligations, an investment in the Fund is neither insured nor guaranteed by the U.S. government. Repurchase agreements could involve certain risks in the event of default or insolvency of the seller, including losses and possible delays or restrictions upon the Fund’s ability to dispose of the underlying securities. To the extent that, in the meantime, the value of the securities that the Fund has purchased has decreased, the Fund could experience a loss. The use of repurchase agreements may produce income that is not exempt from state personal income tax. Please see the Fund’s prospectus for a more complete discussion of these and other risks and the Fund’s investment strategies.

All investments are subject to risk including the possible loss of principal. Past performance is no guarantee of future results.

Portfolio at a glance^† (unaudited)

U.S. Treasury Reserves Portfolio

The Fund invests all of its investable assets in U.S. Treasury Reserves Portfolio, the investment breakdown of which is shown below.

Investment breakdown (%) as a percent of total investments

Fund expenses (unaudited)

Example

As a shareholder of the Fund, you may incur two types of costs: (1) transaction costs and (2) ongoing costs, including management fees and other Fund expenses. This example is intended to help you understand your ongoing costs (in dollars) of investing in the Fund and to compare these costs with the ongoing costs of investing in other mutual funds.

This example is based on an investment of $1,000 invested on September 1, 2023 and held for the six months ended February 29, 2024.

Actual expenses

The table below titled “Based on actual total return” provides information about actual account values and actual expenses. You may use the information provided in this table, together with the amount you invested, to estimate the expenses that you paid over the period. To estimate the expenses you paid on your account, divide your ending account value by $1,000 (for example, an $8,600 ending account value divided by $1,000 = 8.6), then multiply the result by the number under the heading entitled “Expenses Paid During the Period”.

Hypothetical example for comparison purposes

The table below titled “Based on hypothetical total return” provides information about hypothetical account values and hypothetical expenses based on the actual expense ratio and an assumed rate of return of 5.00% per year before expenses, which is not the Fund’s actual return. The hypothetical account values and expenses may not be used to estimate the actual ending account balance or expenses you paid for the period. You may use the information provided in this table to compare the ongoing costs of investing in the Fund and other funds. To do so, compare the 5.00% hypothetical example relating to the Fund with the 5.00% hypothetical examples that appear in the shareholder reports of the other funds.

Please note that the expenses shown in the table below are meant to highlight your ongoing costs only and do not reflect any transactional costs. Therefore, the table is useful in comparing ongoing costs only, and will not help you determine the relative total costs of owning different funds. In addition, if these transaction costs were included, your costs would have been higher.

Statement of assets and liabilities (unaudited)

February 29, 2024

See Notes to Financial Statements.

Statement of operations (unaudited)

For the Six Months Ended February 29, 2024

See Notes to Financial Statements.

Statements of changes in net assets

See Notes to Financial Statements.

Financial highlights

See Notes to Financial Statements.

Financial highlights (cont’d)

See Notes to Financial Statements.

Notes to financial statements (unaudited)

1. Organization and significant accounting policies

Western Asset Premier Institutional U.S. Treasury Reserves (the “Fund”) is a separate diversified investment series of Legg Mason Partners Institutional Trust (the “Trust”). The Trust, a Maryland statutory trust, is registered under the Investment Company Act of 1940, as amended (the “1940 Act”), as an open-end management investment company. The Fund invests all of its investable assets in U.S. Treasury Reserves Portfolio (the “Portfolio”), a separate investment series of Master Portfolio Trust, that has the same investment objective as the Fund.

The financial statements of the Portfolio, including the schedule of investments, are contained elsewhere in this report and should be read in conjunction with the Fund’s financial statements.

The Fund follows the accounting and reporting guidance in Financial Accounting Standards Board (“FASB”) Accounting Standards Codification Topic 946, Financial Services – Investment Companies (“ASC 946”). The following are significant accounting policies consistently followed by the Fund and are in conformity with U.S. generally accepted accounting principles (“GAAP”), including, but not limited to, ASC 946. Estimates and assumptions are required to be made regarding assets, liabilities and changes in net assets resulting from operations when financial statements are prepared. Changes in the economic environment, financial markets and any other parameters used in determining these estimates could cause actual results to differ. Subsequent events have been evaluated through the date the financial statements were issued.

(a) Investment valuation. The Fund records its investment in the Portfolio at value. The value of such investment in the Portfolio reflects the Fund’s proportionate interest (7.7% at February 29, 2024) in the net assets of the Portfolio.

GAAP establishes a disclosure hierarchy that categorizes the inputs to valuation techniques used to value assets and liabilities at measurement date. The disclosure and valuation of securities held by the Portfolio are discussed in Note 1(a) of the Portfolio’s Notes to Financial Statements, which are included elsewhere in this report.

(b) Investment transactions and investment income. Net investment income of the Portfolio is allocated pro rata, based on respective ownership interests, among the Fund and other investors in the Portfolio (the “Holders”) at the time of such determination. Gross realized gains and/or losses of the Portfolio are allocated to the Holders in a manner such that the net asset values per share of each Holder, after each such allocation, is closer to the total of all Holders’ net asset values divided by the aggregate number of shares outstanding for all Holders. The Fund also pays certain other expenses which can be directly attributed to the Fund.

(c) Distributions to shareholders. Distributions from net investment income on the shares of the Fund are declared each business day and are paid monthly. Distributions of net realized gains, if any, are declared at least annually. Distributions to shareholders of the Fund are recorded on the ex-dividend date and are determined in accordance with income tax regulations, which may differ from GAAP.

Notes to financial statements (unaudited) (cont’d)

(d) Share class accounting. Investment income, common expenses and realized gains (losses) on investments are allocated to the various classes of the Fund on the basis of daily net assets of each class. Fees relating to a specific class are charged directly to that share class.

(e) Federal and other taxes. It is the Fund’s policy to comply with the federal income and excise tax requirements of the Internal Revenue Code of 1986 (the “Code”), as amended, applicable to regulated investment companies. Accordingly, the Fund intends to distribute its taxable income and net realized gains, if any, to shareholders in accordance with timing requirements imposed by the Code. Therefore, no federal or state income tax provision is required in the Fund’s financial statements.

Management has analyzed the Fund’s tax positions taken on income tax returns for all open tax years and has concluded that as of August 31, 2023, no provision for income tax is required in the Fund’s financial statements. The Fund’s federal and state income and federal excise tax returns for tax years for which the applicable statutes of limitations have not expired are subject to examination by the Internal Revenue Service and state departments of revenue.

(f) Reclassification. GAAP requires that certain components of net assets be reclassified to reflect permanent differences between financial and tax reporting. These reclassifications have no effect on net assets or net asset value per share.

2. Investment management agreement and other transactions with affiliates

Franklin Templeton Fund Adviser, LLC (“FTFA”) (formerly known as Legg Mason Partners Fund Advisor, LLC prior to November 30, 2023) is the Fund’s and the Portfolio’s investment manager and Western Asset Management Company, LLC (“Western Asset”) is the Fund’s and the Portfolio’s subadviser. FTFA and Western Asset are indirect, wholly-owned subsidiaries of Franklin Resources, Inc. (“Franklin Resources”).

Under the investment management agreement, the Fund pays an investment management fee, calculated daily and paid monthly, in accordance with the following breakpoint schedule:

Since the Fund invests all of its investable assets in the Portfolio, the investment management fee of the Fund will be reduced by the investment management fee allocated to the Fund by the Portfolio.

FTFA provides administrative and certain oversight services to the Fund. FTFA delegates to the subadviser the day-to-day portfolio management of the Fund. For its services, FTFA pays Western Asset a fee monthly, at an annual rate equal to 70% of the net management fee it receives from the Fund.

As a result of expense limitation arrangements between the Fund and FTFA, the ratio of total annual fund operating expenses, other than interest, brokerage, taxes, extraordinary expenses and acquired fund fees and expenses, to average net assets of Capital Shares and Premium Shares did not exceed 0.12% and 0.14%, respectively. These expense limitation arrangements cannot be terminated prior to December 31, 2024 without the Board of Trustees’ consent. Additional amounts may be voluntarily waived and/or reimbursed from time to time.

During the six months ended February 29, 2024, fees waived and/or expenses reimbursed amounted to $939,771.

FTFA is permitted to recapture amounts waived and/or reimbursed to a class during the same fiscal year if the class’ total annual fund operating expenses have fallen to a level below the expense limitation (“expense cap”) in effect at the time the fees were earned or the expenses incurred. In no case will FTFA recapture any amount that would result, on any particular business day of the Fund, in the class’ total annual fund operating expenses exceeding the expense cap or any other lower limit then in effect.

Franklin Distributors, LLC (“Franklin Distributors”) serves as the Fund’s sole and exclusive distributor. Franklin Distributors is an indirect, wholly-owned broker-dealer subsidiary of Franklin Resources.

All officers and one Trustee of the Trust are employees of Franklin Resources or its affiliates and do not receive compensation from the Trust.

As of February 29, 2024, Franklin Resources and its affiliates owned 91% of the Fund.

3. Class specific expenses, waivers and/or expense reimbursements

For the six months ended February 29, 2024, class specific expenses were as follows:

For the six months ended February 29, 2024, waivers and/or expense reimbursements by class were as follows:

Notes to financial statements (unaudited) (cont’d)

4. Distributions to shareholders by class

5. Shares of beneficial interest

At February 29, 2024, the Trust had an unlimited number of shares of beneficial interest authorized with a par value of $0.00001 per share. The Fund has the ability to issue multiple classes of shares. Each class of shares represents an identical interest and has the same rights, except that each class bears certain direct expenses, including those specifically related to the distribution of its shares.

Transactions in shares of each class were as follows:

Because the Fund has maintained a $1.00 net asset value per share from inception, the number of shares sold, shares issued on reinvestment of dividends declared, and shares repurchased is equal to the dollar amount shown in the Statements of Changes in Net Assets for the corresponding fund share transactions.

6. Deferred capital losses

As of August 31, 2023, the Fund had deferred capital losses of $33,961, which have no expiration date, that will be available to offset future taxable capital gains.

Schedule of investments (unaudited)

February 29, 2024

U.S. Treasury Reserves Portfolio

(Percentages shown based on Portfolio net assets)

See Notes to Financial Statements.

Schedule of investments (unaudited) (cont’d)

February 29, 2024

U.S. Treasury Reserves Portfolio

(Percentages shown based on Portfolio net assets)

See Notes to Financial Statements.

U.S. Treasury Reserves Portfolio

See Notes to Financial Statements.

Statement of assets and liabilities (unaudited)

February 29, 2024

See Notes to Financial Statements.

Statement of operations (unaudited)

For the Six Months Ended February 29, 2024

See Notes to Financial Statements.

Statements of changes in net assets

See Notes to Financial Statements.

Financial highlights

See Notes to Financial Statements.

Notes to financial statements (unaudited)

1. Organization and significant accounting policies

U.S. Treasury Reserves Portfolio (the “Portfolio”) is a separate diversified investment series of Master Portfolio Trust (the “Trust”). The Trust, a Maryland statutory trust, is registered under the Investment Company Act of 1940, as amended (the “1940 Act”), as an open-end management investment company. The Declaration of Trust permits the Trustees to issue beneficial interests in the Portfolio. At February 29, 2024, all investors in the Portfolio were funds advised or administered by the investment manager of the Portfolio and/or its affiliates.

The Portfolio follows the accounting and reporting guidance in Financial Accounting Standards Board (“FASB”) Accounting Standards Codification Topic 946, Financial Services – Investment Companies (“ASC 946”). The following are significant accounting policies consistently followed by the Portfolio and are in conformity with U.S. generally accepted accounting principles (“GAAP”), including, but not limited to, ASC 946. Estimates and assumptions are required to be made regarding assets, liabilities and changes in net assets resulting from operations when financial statements are prepared. Changes in the economic environment, financial markets and any other parameters used in determining these estimates could cause actual results to differ. Subsequent events have been evaluated through the date the financial statements were issued.

(a) Investment valuation. In accordance with Rule 2a-7 under the 1940 Act, money market instruments are valued at amortized cost, which approximates market value. This method involves valuing portfolio securities at their cost and thereafter assuming a constant amortization to maturity of any discount or premium. The Portfolio’s use of amortized cost is subject to its compliance with certain conditions as specified by Rule 2a-7 under the 1940 Act.

Pursuant to policies adopted by the Board of Trustees, the Portfolio’s manager has been designated as the valuation designee and is responsible for the oversight of the daily valuation process. The Portfolio’s manager is assisted by the Global Fund Valuation Committee (the “Valuation Committee”). The Valuation Committee is responsible for making fair value determinations, evaluating the effectiveness of the Portfolio’s pricing policies, and reporting to the Board of Trustees.

The Portfolio uses valuation techniques to measure fair value that are consistent with the market approach and/or income approach, depending on the type of security and the particular circumstance. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable securities. The income approach uses valuation techniques to discount estimated future cash flows to present value.

GAAP establishes a disclosure hierarchy that categorizes the inputs to valuation techniques used to value assets and liabilities at measurement date. These inputs are summarized in the three broad levels listed below:

The inputs or methodologies used to value securities are not necessarily an indication of the risk associated with investing in those securities.

The following is a summary of the inputs used in valuing the Portfolio’s assets carried at fair value:

(b) Repurchase agreements. The Portfolio may enter into repurchase agreements with institutions that its subadviser has determined are creditworthy. Each repurchase agreement is recorded at cost. Under the terms of a typical repurchase agreement, the Portfolio acquires a debt security subject to an obligation of the seller to repurchase, and of the Portfolio to resell, the security at an agreed-upon price and time, thereby determining the yield during the Portfolio’s holding period. When entering into repurchase agreements, it is the Portfolio’s policy that its custodian or a third party custodian, acting on the Portfolio’s behalf, take possession of the underlying collateral securities, the market value of which, at all times, at least equals the principal amount of the repurchase transaction, including accrued interest. To the extent that any repurchase transaction maturity exceeds one business day, the value of the collateral is marked-to-market and measured against the value of the agreement in an effort to ensure the adequacy of the collateral. If the counterparty defaults, the Portfolio generally has the right to use the collateral to satisfy the terms of the repurchase transaction. However, if the market value of the collateral declines during the period in which the Portfolio seeks to assert its rights or if bankruptcy proceedings are commenced with respect to the seller of the security, realization of the collateral by the Portfolio may be delayed or limited.

(c) Securities traded on a when-issued and delayed delivery basis. The Portfolio may trade securities on a when-issued or delayed delivery basis. In when-issued and

Notes to financial statements (unaudited) (cont’d)

delayed delivery transactions, the securities are purchased or sold by the Portfolio with payment and delivery taking place in the future in order to secure what is considered to be an advantageous price and yield to the Portfolio at the time of entering into the transaction.

Purchasing such securities involves risk of loss if the value of the securities declines prior to settlement. These securities are subject to market fluctuations and their current value is determined in the same manner as for other securities.

(d) Interest income and expenses. Interest income (including interest income from payment-in-kind securities) consists of interest accrued and discount earned (including both original issue and market discount adjusted for amortization of premium) on the investments of the Portfolio. Expenses of the Portfolio are accrued daily. The Portfolio bears all costs of its operations other than expenses specifically assumed by the investment manager.

(e) Method of allocation. Net investment income of the Portfolio is allocated pro rata, based on respective ownership interests, among the Fund and other investors in the Portfolio (the “Holders”) at the time of such determination. Gross realized gains and/or losses of the Portfolio are allocated to the Holders in a manner such that the net asset values per share of each Holder, after each such allocation, is closer to the total of all Holders’ net asset values divided by the aggregate number of shares outstanding for all Holders.

(f) Compensating balance arrangements. The Portfolio has an arrangement with its custodian bank whereby a portion of the custodian’s fees is paid indirectly by credits earned on the Portfolio’s cash on deposit with the bank.

(g) Income taxes. The Portfolio is classified as a partnership for federal income tax purposes. As such, each investor in the Portfolio is treated as owner of its proportionate share of the net assets, income, expenses and realized gains and losses of the Portfolio. Therefore, no federal income tax provision is required. It is intended that the Portfolio’s assets will be managed so an investor in the Portfolio can satisfy the requirements of Subchapter M of the Internal Revenue Code.

Management has analyzed the Portfolio’s tax positions taken on income tax returns for all open tax years and has concluded that as of August 31, 2023, no provision for income tax is required in the Portfolio’s financial statements. The Portfolio’s federal and state income tax returns for tax years for which the applicable statutes of limitations have not expired are subject to examination by the Internal Revenue Service and state departments of revenue.

(h) Other. Purchases, maturities and sales of money market instruments are accounted for on the date of the transaction. Realized gains and losses are calculated on the identified cost basis.

2. Investment management agreement and other transactions with affiliates

Franklin Templeton Fund Adviser, LLC (“FTFA”) (formerly known as Legg Mason Partners Fund Advisor, LLC prior to November 30, 2023) is the Portfolio’s investment manager and Western Asset Management Company, LLC (“Western Asset”) is the Portfolio’s subadviser. FTFA and Western Asset are indirect, wholly-owned subsidiaries of Franklin Resources, Inc. (“Franklin Resources”).

Under the investment management agreement, the Portfolio pays an investment management fee, calculated daily and paid monthly, at an annual rate of 0.10% of the Portfolio’s average daily net assets.

FTFA provides administrative and certain oversight services to the Portfolio. FTFA delegates to the subadviser the day-to-day portfolio management of the Portfolio. For its services, FTFA pays Western Asset a fee monthly, at an annual rate equal to 70% of the net management fee it receives from the Portfolio.

As a result of the investment management agreement between FTFA and the feeder fund, FTFA has agreed to waive 0.10% of Portfolio expenses, attributable to the Portfolio’s investment management fee. Additional amounts may be voluntarily waived and/or reimbursed from time to time.

During the six months ended February 29, 2024, fees waived and/or expenses reimbursed amounted to $8,007,625.

FTFA is permitted to recapture amounts waived and/or reimbursed to the Portfolio during the same fiscal year under certain circumstances.

All officers and one Trustee of the Trust are employees of Franklin Resources or its affiliates and do not receive compensation from the Trust.

3. Derivative instruments and hedging activities

During the six months ended February 29, 2024, the Portfolio did not invest in derivative instruments.

Western Asset

Premier Institutional U.S. Treasury Reserves

Trustees

Robert Abeles, Jr.

Jane F. Dasher

Anita L. DeFrantz

Susan B. Kerley

Michael Larson

Ronald L. Olson

Avedick B. Poladian

William E.B. Siart

Chairman

Jaynie M. Studenmund

Peter J. Taylor

Jane Trust

* Formerly known as Legg Mason Partners Fund Advisor, LLC.

Investment manager

Franklin Templeton Fund Adviser, LLC*

Subadviser

Western Asset Management Company, LLC

Distributor

Franklin Distributors, LLC

Custodian

The Bank of New York Mellon

Transfer agent

BNY Mellon Investment Servicing (US) Inc.

500 Ross Street, 154-0520

Pittsburgh, PA 15262

Independent registered public accounting firm

PricewaterhouseCoopers LLP

Baltimore, MD

Western Asset Premier Institutional U.S. Treasury Reserves

The Fund is a separate investment series of Legg Mason Partners Institutional Trust, a Maryland statutory trust.

Western Asset Premier Institutional U.S. Treasury Reserves

Legg Mason Funds

620 Eighth Avenue, 47th Floor

New York, NY 10018

The Fund files its complete schedule of portfolio holdings with the Securities and Exchange Commission (“SEC”) each month on Form N-MFP. The Fund’s reports on Form N-MFP are available on the SEC’s website at www.sec.gov. The Fund makes portfolio holdings available to shareholders on its website at www.franklintempleton.com.

Information on how the Fund voted proxies relating to portfolio securities during the prior 12-month period ended June 30th of each year and a description of the policies and procedures that the Fund uses to determine how to vote proxies related to portfolio transactions are available (1) without charge, upon request, by calling the Fund at 1-877-721-1926 or 1-203-703-6002, (2) at www.franklintempleton.com and (3) on the SEC’s website at www.sec.gov.

This report is submitted for the general information of the shareholders of Western Asset Premier Institutional U.S. Treasury Reserves. This report is not authorized for distribution to prospective investors in the Fund unless preceded or accompanied by a current prospectus.

Investors should consider the Fund’s investment objectives, risks, charges and expenses carefully before investing. The prospectus contains this and other important information about the Fund. Please read the prospectus carefully before investing.

www.franklintempleton.com

© 2024 Franklin Distributors, LLC, Member FINRA/SIPC. All rights reserved.

Franklin Templeton Funds Privacy and Security Notice

Your Privacy and the Security of Your Personal Information is Very Important to US

This Privacy and Security Notice (the “Privacy Notice”) addresses the Funds’ privacy and data protection practices with respect to nonpublic personal information the Fund receives. The Legg Mason Funds include the Western Asset Money Market Funds (Funds) sold by the Funds’ distributor, Franklin Distributors, LLC, as well as Legg Mason-sponsored closed-end funds. The provisions of this Privacy Notice apply to your information both while you are a shareholder and after you are no longer invested with the Funds.

The Type of Nonpublic Personal Information the Funds Collect About You

The Funds collect and maintain nonpublic personal information about you in connection with your shareholder account. Such information may include, but is not limited to:

How the Funds Use Nonpublic Personal Information About You

The Funds do not sell or share your nonpublic personal information with third parties or with affiliates for their marketing purposes, unless you have authorized the Funds to do so. The Funds do not disclose any nonpublic personal information about you except as may be required to perform transactions or services you have authorized or as permitted or required by law. The Funds may disclose information about you to:

Franklin Templeton Funds Privacy and Security Notice (cont’d)

Except as otherwise permitted by applicable law, companies acting on the Funds’ behalf, including those outside the United States, are contractually obligated to keep nonpublic personal information the Funds provide to them confidential and to use the information the Funds share only to provide the services the Funds ask them to perform.

The Funds may disclose nonpublic personal information about you when necessary to enforce their rights or protect against fraud, or as permitted or required by applicable law, such as in connection with a law enforcement or regulatory request, subpoena, or similar legal process. In the event of a corporate action or in the event a Fund service provider changes, the Funds may be required to disclose your nonpublic personal information to third parties. While it is the Funds’ practice to obtain protections for disclosed information in these types of transactions, the Funds cannot guarantee their privacy policy will remain unchanged.

Keeping You Informed of the Funds’ Privacy and Security Practices

The Funds will notify you annually of their privacy policy as required by federal law. While the Funds reserve the right to modify this policy at any time, they will notify you promptly if this privacy policy changes.

The Funds’ Security Practices

The Funds maintain appropriate physical, electronic and procedural safeguards designed to guard your nonpublic personal information. The Funds’ internal data security policies restrict access to your nonpublic personal information to authorized employees, who may use your nonpublic personal information for Fund business purposes only.

Although the Funds strive to protect your nonpublic personal information, they cannot ensure or warrant the security of any information you provide or transmit to them, and you do so at your own risk. In the event of a breach of the confidentiality or security of your nonpublic personal information, the Funds will attempt to notify you as necessary so you can take appropriate protective steps. If you have consented to the Funds using electronic communications or electronic delivery of statements, they may notify you under such circumstances using the most current email address you have on record with them.

In order for the Funds to provide effective service to you, keeping your account information accurate is very important. If you believe that your account information is incomplete, not accurate or not current, if you have questions about the Funds’ privacy practices, or our use of your nonpublic personal information, write the Funds using the contact information on your account statements, email the Funds by clicking on the Contact Us section of the Funds’ website at www.franklintempleton.com, or contact the Funds at 1-877-721-1926 for the Western Asset Money Market Funds or 1-888-777-0102 for the Legg Mason-sponsored closed-end funds. For additional information related to certain state privacy rights, please visit https:// www.franklintempleton.com/help/privacy-policy.

Revised December 2023.

www.franklintempleton.com

^© 2024 Franklin Distributors, LLC, Member FINRA/SIPC. All rights reserved.

WASX581628 4/24 SR24-4855

Not applicable.

Not applicable.

Not applicable.

Not applicable.

Included herein under Item 1.

Not applicable.

Not applicable.

Not applicable.

Not applicable.

Not applicable.

(a) Not applicable.

(b) Not applicable.

(a) (1) Not applicable.

Exhibit  99.CODE ETH

(a) (2)  Certifications pursuant to section 302 of the Sarbanes-Oxley Act of 2002 attached hereto.

Exhibit 99.CERT

(b) Certifications pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 attached hereto.

Exhibit 99.906CERT

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this Report to be signed on its behalf by the undersigned, there unto duly authorized.

Legg Mason Partners Institutional Trust

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

ATTACHMENTS / EXHIBITS

CERTIFICATION 302

CERTIFICATION 906