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Summary Prospectus

August 31, 2026

Disclosure contained herein relates to all classes of the Fund, as listed below, unless otherwise noted.

Share Class | Ticker

A | FMTAX

Institutional | FSHIX

Service | FSHSX

Federated Hermes Short-Intermediate

Municipal Fund

A Portfolio of Federated Hermes Short-Intermediate Duration Municipal Trust

Before you invest, you may want to review the Fund’s Prospectus, which contains more information about the Fund and its risks. You can find the Fund’s Prospectus and other information about the Fund, including the Statement of Additional Information and most recent reports to shareholders, online at FederatedHermes.com/us/FundInformation. You can also get this information at no cost by calling 1-800-341-7400, by sending an email request via Contact Us on FederatedHermes.com/us, or from a financial intermediary through which Shares of the Fund may be bought or sold. The Fund’s Prospectus and Statement of Additional Information, both dated August 31, 2026, are incorporated by reference into this Summary Prospectus.

A mutual fund seeking to provide dividend income which is exempt from federal regular income tax by investing its assets so that, normally, distributions of annual interest income are exempt from federal regular income tax.

As with all mutual funds, the Securities and Exchange Commission (SEC) has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

Not FDIC Insured ▪ May Lose Value ▪ No Bank Guarantee

Fund Summary Information

Federated Hermes Short-Intermediate Municipal Fund (the “Fund”)

RISK/RETURN SUMMARY: INVESTMENT OBJECTIVE

The Fund’s investment objective is to provide dividend income which is exempt from federal regular income tax.

RISK/RETURN SUMMARY: FEES AND EXPENSES

This table describes the fees and expenses that you may pay if you buy, hold and sell Class A Shares (A), Institutional Shares (IS) or Service Shares (SS) of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for certain sales charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in certain classes (e.g., A class) of Federated Hermes funds. More information about these and other discounts is available from your financial professional, in the “What Do Shares Cost?” section of the Prospectus on page 19 and in “Appendix B” to this Prospectus.

Shareholder Fees (fees paid directly from your investment)

	A	IS	SS
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	1.00%	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of original purchase price or redemption proceeds, as applicable)	None	None	None
Maximum Sales Charge (Load) Imposed on Reinvested Dividends (and other Distributions) (as a percentage of offering price)	None	None	None
Redemption Fee (as a percentage of amount redeemed, if applicable)	None	None	None
Exchange Fee	None	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	A	IS	SS
Management Fee	0.39%	0.39%	0.39%
Distribution (12b-1) Fee	0.00%1	None	None
Other Expenses	0.47%	0.47%	0.47%
Total Annual Fund Operating Expenses	0.86%	0.86%	0.86%
Fee Waivers and/or Expense Reimbursements2	(0.21)%	(0.46)%	(0.21)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.65%	0.40%	0.65%

The Fund has adopted a Distribution (12b-1) Plan for its Class A Shares pursuant to which the A class

of the Fund may incur and pay a Distribution (12b-1) Fee of up to a maximum of 0.05%. No such fee

is currently incurred and paid by the A class of the Fund. The A class of the Fund will not incur and

pay such a Distribution (12b-1) Fee until such time as approved by the Board of Trustees

(the “Trustees”).

Under the investment advisory contract, the Adviser is required to reimburse/waive the amount,

limited to the amount of the management fee, by which the Fund’s aggregate annual operating

expenses, including the management fee, but excluding interest, taxes, brokerage commissions,

expenses of registering and qualifying the Fund and its shares under federal and state laws,

expenses of withholding taxes and extraordinary expenses exceed (after voluntary waivers and

reimbursements) 0.45% of the Fund’s IS class average daily net assets. Acquired fund fees and

expenses are not direct obligations of the Fund and are not contractual reimbursements under the

investment advisory contract. In addition, the Adviser and certain of its affiliates on their own

initiative have agreed to waive certain amounts of their respective fees and/or reimburse expenses.

Total annual fund operating expenses (excluding acquired fund fees and expenses, interest expense,

extraordinary expenses and proxy-related expenses, if any) paid by the Fund’s A, IS and SS classes

(after the voluntary waivers and/or reimbursements) will not exceed 0.65%, 0.40% and 0.65% (the

“Fee Limit”), respectively, up to but not including the later of (the “Termination Date”):

(a) September 1, 2027; or (b) the date of the Fund’s next effective Prospectus. While the Adviser and

its affiliates currently do not anticipate terminating or increasing these arrangements prior to the

Termination Date, these arrangements may only be terminated or the Fee Limit increased prior to the

Termination Date with the approval of the Trustees.

Example

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.

The Example assumes that you invest $10,000 for the time periods indicated and then redeem or hold 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 operating expenses remain the same. The Example does not reflect sales charges (loads) on reinvested dividends. If these sales charges (loads) were included, your costs would be higher. Although your actual costs and returns may be higher or lower, based on these assumptions your cost would be:

Share Class	1 Year	3 Years	5 Years	10 Years
A	$187	$372	$572	$1,150
IS	$88	$274	$477	$1,061
SS	$88	$274	$477	$1,061

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund Shares are held in a taxable account. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 26% of the average value of its portfolio.

RISK/RETURN SUMMARY: INVESTMENTS, RISKS and PERFORMANCE

What are the Fund’s Main Investment Strategies?

The Fund pursues its objective by investing its assets so that normally distributions of annual interest income are exempt from federal regular income tax. The Adviser may invest the Fund’s assets without limitation in securities whose interest may be subject to (or may be a specific preference item for purposes of) the federal alternative minimum tax (AMT) for individuals. With respect to such investments, interest from the Fund’s investments may be subject to (or may be a specific preference item for purposes of) the AMT.

The Fund does not limit itself to securities of a particular maturity range. The Fund’s dollar-weighted average portfolio duration will be less than five years. “Duration” measures the sensitivity of a security’s price to changes in interest rates. The Adviser may lengthen or shorten duration from time to time based on its interest rate outlook.

The Fund will invest at least a majority of its assets in securities rated investment-grade (or unrated securities of comparable quality), and may purchase securities rated below investment grade (or unrated securities of comparable quality), which are also known as junk bonds, up to 49% of its assets. Investment-grade securities are securities that receive investment-grade ratings (i.e., generally ratings in the first, second, third or fourth highest rating category) by a nationally recognized statistical rating organization (NRSRO) or unrated securities of comparable quality. For example, securities rated AAA, AA, A or BBB (including modifiers, sub-categories or gradations) by S&P Global Ratings (“S&P Global”), an NRSRO, would be rated in the first, second, third or fourth ratings category, respectively. Securities rated below investment grade (or noninvestment-grade securities) are securities that do not receive investment-grade ratings (i.e., generally ratings below one of the four highest rating categories) by an NRSRO or unrated securities of comparable quality. For example, securities rated B or BB (including modifiers, sub-categories or gradations) by S&P Global would be noninvestment-grade securities. The presence of a ratings modifier, sub-category, or gradation (for example, a (+) or (-)) is intended to show relative standing within the major rating categories and does not affect the security credit rating for purposes of the Fund’s investment parameters. The Fund does not have a specific minimum quality rating.

The securities in which the Fund may principally invest include tax-exempt securities, which may include, for example, general obligation bonds, special revenue bonds, private activity bonds, inverse floaters, municipal mortgage-backed securities, variable rate demand instruments and municipal notes. Certain of the tax-exempt securities in which the Fund invests may be subject to credit enhancement. The Fund also may principally invest in derivative contracts, in particular, futures contracts, option contracts and swap contracts, and/or hybrid instruments to implement its investment strategies. For example, the Fund may use derivative contracts or hybrid instruments to increase or decrease the portfolio’s exposure to the investment(s) underlying the derivative or hybrid instrument in an attempt to benefit from changes in the value of the

underlying instrument(s), to gain exposure to the municipal bond sector, to increase or decrease the effective duration of the Fund’s portfolio or to hedge against potential losses. There can be no assurance that the Fund’s use of derivative contracts or hybrid instruments will work as intended. Derivative investments made by the Fund that provide investment exposure to investments suggested by the Fund’s name are included within the Fund’s 80% policy and are calculated at notional value.

The Fund also may invest in certain securities or other investments (such as market discount bonds, credit default swaps and other derivative transactions) that will likely cause the Fund to realize a limited amount of ordinary income or short-term capital gains (which are treated as ordinary income for federal income tax purposes).

Under normal circumstances, the Fund will invest its assets so that at least 80% of the income that it distributes will be exempt from federal regular income tax. This policy may not be changed without shareholder approval.

What are the Main (or Principal) Risks of Investing in the Fund?

All mutual funds take investment risks. Therefore, it is possible to lose money by investing in the Fund. The primary factors that may reduce the Fund’s returns include:

■ Tax-Exempt Securities Risk. The amount of public information available about tax-exempt securities is generally less than for corporate equities or bonds. The secondary market for tax-exempt securities also tends to be less well-developed and less liquid than many other securities markets, which may limit the Fund’s ability to sell its tax-exempt securities at attractive prices. Special factors, such as legislative changes, and state and local economic and business developments, may adversely affect the yield and/or value of the Fund’s investments in tax-exempt securities. Changes in tax policy could adversely affect the tax-exempt status of securities held by the Fund. Tax-exempt issuers can and have defaulted on obligations, been downgraded or commenced insolvency proceedings. Like other issuers and securities, the likelihood that the credit risk associated with such issuers and such securities will increase is greater during times of economic stress and financial instability.

■ Interest Rate Risk. Prices of fixed-income securities (including tax-exempt securities) generally fall when interest rates rise. The longer the duration of a fixed-income security, the more susceptible it is to interest rate risk. Recent and potential future changes in monetary policy made by central banks and/or their governments are likely to affect the level of interest rates.

■ Issuer Credit Risk. It is possible that interest or principal on securities will not be paid when due. Noninvestment-grade securities generally have a higher default risk than investment-grade securities. Such non-payment or default may reduce the value of the Fund’s portfolio holdings, its share price and its performance.

■ Counterparty Risk. Counterparty risk includes the possibility that a party to a transaction involving the Fund may fail to meet its obligations. This could cause the Fund to lose money or to lose the benefit of the transaction or prevent the Fund from selling or buying other securities to implement its investment strategies.

■ Liquidity Risk. Certain securities in which the Fund invests may be less readily marketable and may be subject to greater fluctuation in price than other securities. These features may make it more difficult to sell or buy a security at a favorable price or time. Noninvestment-grade securities generally have less liquidity than investment-grade securities. Liquidity risk also refers to the possibility that the Fund may not be able to sell a security or close out a derivative contract when it wants to. Over-the-counter derivative contracts generally carry greater liquidity risk than exchange-traded contracts.

■ Tax Risk. In order to be tax-exempt, tax-exempt securities must meet certain legal requirements. Failure to meet such requirements may cause the interest received and distributed by the Fund to shareholders to be taxable. The Fund and the Adviser will rely on the opinions of issuers’ bond counsel on the tax-exempt status of interest on municipal bonds. The Fund and the Adviser do not guarantee or represent that such opinions are correct when issued or that underlying facts and circumstances will not change such that such opinions remain correct, and the Fund and the Adviser will not undertake independent investigations to review the bases for or ongoing effect of those tax opinions. Income from tax-exempt securities held by the Fund could also become taxable because of changes in tax laws or interpretations by taxing authorities, resulting in a higher tax liability for shareholders and potentially adversely impacting Fund performance. The federal income tax treatment of payments in respect of certain derivative contracts is unclear. The Fund also may invest in market discount bonds, enter into credit default swap arrangements and other derivative transactions, and engage in other permissible activities that will likely cause the Fund to realize a limited amount of ordinary income or short-term capital gains (which are treated as ordinary income for federal income tax purposes). Consequently, for each of these reasons, the Fund may receive payments, and make distributions, that are treated as ordinary income for federal income tax purposes. Income from the Fund also may be subject to AMT.

■ Leverage Risk. Leverage risk is created when an investment, which includes, for example, a derivative contract, exposes the Fund to a level of risk that exceeds the amount invested. Changes in the value of such an investment magnify the Fund’s risk of loss and potential for gain. Investments can have these same results if their returns are based on a multiple of a specified index, security or other benchmark.

■ Call Risk. The Fund’s performance may be adversely affected by the possibility that an issuer of a security held by the Fund may redeem the security prior to maturity at a price below or above its current market value.

■ Sector Risk. A substantial part of the Fund’s portfolio may be comprised of securities issued or credit enhanced by companies in similar businesses, or with other similar characteristics. As a result, the Fund will be more susceptible to any economic, business, political or other developments which generally affect these issuers or entities.

■ Prepayment and Extension Risk. When homeowners prepay their mortgages in response to lower interest rates, the Fund will be required to reinvest the proceeds at the lower interest rates available. Also, when interest rates fall, the price of municipal mortgage-backed securities may not rise to as great an extent as that of other fixed-income securities. When interest rates rise, homeowners are less likely to prepay their mortgages. A decreased rate of prepayments lengthens the expected maturity of a mortgage-backed security, and the price of mortgage-backed securities may decrease more than the price of other fixed-income securities when interest rates rise.

■ Credit Enhancement Risk. The securities in which the Fund invests may be subject to credit enhancement (for example, guarantees, letters of credit or bond insurance). If the credit quality of the credit enhancement provider (for example, a bank or bond insurer) is downgraded, the rating on a security credit enhanced by such credit enhancement provider also may be downgraded. Having multiple securities credit enhanced by the same enhancement provider will increase the adverse effects on the Fund that are likely to result from a downgrading of, or a default by, such an enhancement provider. Adverse developments in the banking or bond insurance industries also may negatively affect the Fund.

■ Risk Associated with Noninvestment-Grade Securities. Securities rated below investment grade may be subject to greater interest rate, credit and liquidity risks than investment-grade securities. These securities are considered speculative with respect to the issuer’s ability to pay interest and repay principal.

■ Risk Related to the Economy. The value of the Fund’s portfolio may decline in tandem with a drop in the overall value of the markets in which the Fund invests and/or other markets. Global economic, political and financial conditions, including geopolitical and other events (e.g., wars, tensions, sanctions and terrorism), legislative changes or shifts in fiscal or monetary policy or reform, industry or economic trends and developments, grid congestion or capacity constraints, natural disasters or public health risks, such as epidemics or pandemics, may, from time to time, and for varying periods of time, have a significant effect on the economies of many nations, including the U.S., and financial markets generally and cause the Fund to experience volatility, illiquidity, loss of value, shareholder redemptions and/or other potentially adverse effects. Among other investments, lower-grade bonds may be particularly sensitive to changes in the economy.

■ Risk of Investing in Derivative Contracts and Hybrid Instruments. Derivative contracts and hybrid instruments involve risks different from, or possibly greater than, risks associated with investing directly in securities

and other traditional investments. Specific risk issues related to the use of such contracts and instruments include valuation and tax issues, increased potential for losses and/or costs to the Fund, and a potential reduction in gains to the Fund. Each of these issues is described in greater detail in this Prospectus. Derivative contracts and hybrid instruments may also involve other risks described in this Prospectus, such as interest rate, credit, liquidity and leverage risks.

■ Exchange-Traded Funds Risk. An investment in an exchange-traded fund (ETF) generally presents the same primary risks as an investment in a conventional fund (i.e., one that is not exchange-traded) that has the same investment objectives, strategies and policies. The price of an ETF can fluctuate up or down, and the Fund could lose money investing in an ETF if the prices of the securities owned by the ETF go down.

■ Technology Risk. The Adviser uses various technologies in managing the Fund, consistent with its investment objective(s) and strategy described in this Prospectus. For example, proprietary and third-party data and systems are utilized to support decision making for the Fund. Data imprecision, software or other technology malfunctions, programming inaccuracies and similar circumstances may impair the performance of these systems, which may negatively affect Fund performance.

The Shares offered by this Prospectus are not deposits or obligations of any bank, are not endorsed or guaranteed by any bank and are not insured or guaranteed by the U.S. government, the Federal Deposit Insurance Corporation, the Federal Reserve Board or any other government agency.

Performance: Bar Chart and Table

Risk/Return Bar Chart

The bar chart and performance table below reflect historical performance data for the Fund and are intended to help you analyze the Fund’s investment risks in light of its historical returns. The bar chart shows the variability of the Fund’s IS class total returns on a calendar year-by-year basis. The Average Annual Total Return Table shows returns for each class averaged over the stated periods, and includes comparative performance information with a broad-based securities market index. The Fund’s performance is also compared to secondary indexes to show how the Fund’s performance compares with the returns of indexes with similar investments. The Fund’s performance will fluctuate, and past performance (before and after taxes) is not necessarily an indication of future results. Updated performance information for the Fund is

available under the “Products” section at FederatedHermes.com/us or by calling 1-800-341-7400.

The Fund’s IS class total return for the six-month period from January 1, 2026 to June 30, 2026, was 1.44%.

Within the periods shown in the bar chart, the Fund’s IS class highest quarterly return was 3.60% (quarter ended December 31, 2023). Its lowest quarterly return was (3.47)% (quarter ended March 31, 2022).

Average Annual Total Return Table

In addition to Return Before Taxes, Return After Taxes is shown for the Fund’s IS class to illustrate the effect of federal taxes on Fund returns. After-tax returns are shown only for the IS class and after-tax returns for the A and SS classes will differ from those shown for the IS class. Actual after-tax returns depend on each investor’s personal tax situation, and are likely to differ from those shown. After-tax returns are calculated using a standard set of assumptions. The stated returns assume the highest historical federal income and capital gains tax rates. These after-tax returns do not reflect the effect of any applicable state and local taxes. After-tax returns are not relevant to investors holding shares through tax-deferred programs, such as a 401(k) Plan, an Individual Retirement Account (IRA) or other tax-advantaged investment plan.

(For the Period Ended December 31, 2025)

	1 Year	5 Year	10 Year
A:
Return Before Taxes	2.88%	1.04%	1.15%
IS:
Return Before Taxes	4.17%	1.48%	1.60%
Return After Taxes on Distributions	4.17%	1.48%	1.60%
Return After Taxes on Distributions and Sale of Fund Shares	3.67%	1.61%	1.64%
SS:
Return Before Taxes	3.82%	1.24%	1.35%
S&P Municipal Bond Index1 (reflects no deduction for fees, expenses or taxes)	4.26%	1.06%	2.44%
S&P Municipal Bond Short Index2 (reflects no deduction for fees, expenses or taxes)	3.64%	1.58%	1.66%
S&P Municipal Bond 1-5 Years Investment Grade 5% Pre-Refunded Index3 (reflects no deduction for fees, expenses or taxes)	4.12%	1.36%	1.70%
Morningstar U.S. Fund Muni National Short Funds Category Average4	3.85%	1.55%	1.59%

The S&P Municipal Bond Index is a broad, market value-weighted index that seeks to measure

the performance of the U.S. municipal bond market. It tracks fixed-rate tax-free bonds and bonds

subject to the alternative minimum tax (AMT). The index includes bonds of all quality – from

AAA to non-rated, including defaulted bonds – from all sectors of the municipal bond market.

The S&P Municipal Bond Short Index consists of bonds in the S&P Municipal Bond Index with a

minimum maturity of six months and a maximum maturity of four years.

The S&P Municipal Bond 1-5 Years Investment Grade 5% Pre-Refunded Index represents the

portion of the S&P Municipal Bond Investment Grade Index composed solely of investment-

grade bonds (those with ratings higher than BBB-/Baa3) with remaining maturities of between

one and five years, 5% of which are pre-refunded.

Morningstar figures represent the average of the total returns reported by all the mutual funds

designated by Morningstar as falling into the respective category indicated. They do not reflect

sales charges.

FUND MANAGEMENT

The Fund’s Investment Adviser is Federated Investment Management Company.

Kyle Stewart, CFA, Senior Portfolio Manager, has been the Fund’s portfolio manager since August of 2022.

Ann Ferentino, CFA, Senior Portfolio Manager, has been the Fund’s portfolio manager since February of 2025.

purchase and sale of fund shares

You may purchase, redeem or exchange Shares of the Fund on any day the New York Stock Exchange is open. Shares may be purchased through a financial intermediary firm that has entered into a Fund selling and/or servicing agreement with the Distributor or an affiliate (“Financial Intermediary”) or directly from the Fund, by wire or by check. Please note that certain purchase restrictions may apply. Redeem or exchange Shares through a financial intermediary or directly from the Fund by telephone at 1-800-341-7400 or by mail.

A Class

The minimum investment amount for the Fund’s A class is generally $1,500 for initial investments and $100 for subsequent investments. There is no minimum initial or subsequent investment amount required for employer-sponsored retirement plans. Certain types of accounts are eligible for lower minimum investments. The minimum investment amount for Systematic Investment Programs is $50.

IS & SS Classes

The minimum initial investment amount for the Fund’s IS and SS classes is generally $1,000,000 and there is no minimum subsequent investment amount. Certain types of accounts are eligible for lower minimum investments. The minimum investment amount for Systematic Investment Programs is $50.

Tax Information

It is anticipated that Fund distributions will be primarily dividends that are exempt from federal regular income tax, although a portion of the Fund’s dividends may not be tax-exempt. Dividends may be subject to state and local taxes. Although the Fund does not seek to realize capital gains, the Fund may realize and distribute capital gains from time to time as a result of the Fund’s normal investment activities. Any Fund distributions of capital gains are taxable at applicable capital gains rates. The Fund is generally not a suitable investment for retirement accounts.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and/or its related companies may pay the intermediary for the sale of Fund Shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.