# EDGAR Filing Document

**Accession Number:** 0000779991
**File Stem:** 0000779991-25-000013
**Filing Date:** 2025-7
**Character Count:** 36535
**Document Hash:** 2d0ec6056c0e604ced33da292dd35768
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000779991-25-000013.hdr.sgml**: 20250724

**ACCESSION NUMBER**: 0000779991-25-000013

**CONFORMED SUBMISSION TYPE**: 497K

**PUBLIC DOCUMENT COUNT**: 3

**FILED AS OF DATE**: 20250724

**DATE AS OF CHANGE**: 20250724

**EFFECTIVENESS DATE**: 20250724

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Eaton Vance Investment Trust
- **CENTRAL INDEX KEY:** 0000779991

**ORGANIZATION NAME:**
- **EIN:** 000000000

**FILING VALUES:**
- **FORM TYPE:** 497K
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 033-01121
- **FILM NUMBER:** 251146207

**BUSINESS ADDRESS:**
- **STREET 1:** ONE POST OFFICE SQUARE
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02109
- **BUSINESS PHONE:** 617-482-8260

**MAIL ADDRESS:**
- **STREET 1:** ONE POST OFFICE SQUARE
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02109

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** EATON VANCE INVESTMENT TRUST
- **DATE OF NAME CHANGE:** 19920703

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** EATON VANCE CALIFORNIA MUNICIPALS TRUST
- **DATE OF NAME CHANGE:** 19920604

## Series and Classes Contracts Data

### Eaton Vance National Ultra-Short Municipal Income Fund (Series ID: S000004825)

| Class ID   | Class Name                                                            | Ticker Symbol   |
|:---|:---|:---|
| C000013046 | Eaton Vance National Ultra-Short Municipal Income Fund Class A        | EXFLX           |
| C000091009 | Eaton Vance National Ultra-Short Municipal Income Fund Class I        | EILMX           |
| C000225142 | Eaton Vance National Ultra-Short Municipal Income Fund Advisers Class |  |

![](itnusmifsp_001.jpg)

Summary Prospectus dated August 1, 2025

**Eaton Vance National Ultra-Short Municipal Income Fund**

Class / Ticker Advisers / EAMLX A / EXFLX I / EILMX

**This Summary Prospectus is designed to provide investors with key fund information in a clear and concise format. Before you invest, you may want to review the Fund's Prospectus and Statement of Additional Information, which contain more information about the Fund and its risks. The Fund's Prospectus and Statement of Additional Information, both dated August 1, 2025, as may be amended or supplemented, are incorporated by reference into this Summary Prospectus. For free paper or electronic copies of the Fund's Prospectus, Statement of Additional Information, annual and semi-annual shareholder reports, and other information about the Fund, go to http://www.eatonvance.com/funddocuments, email a request to contact@eatonvance.com, call 1-800-262-1122, or ask any financial advisor, bank, or broker-dealer who offers shares of the Fund. Unless otherwise noted, page number references refer to the current Prospectus for this Fund.**

**Investment Objective**

The Fund's investment objective is to provide current income exempt from regular federal income tax.

**Fees and Expenses of the Fund**

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. **Investors may also pay commissions or other fees to their financial intermediary, which are not reflected below.** You may qualify for a reduced sales charge on purchases of Class A shares if you invest, or agree to invest over a 13-month period, at least $100,000 in Eaton Vance funds. Certain financial intermediaries also may offer variations in Fund sales charges to their customers as described in Appendix A – Financial Intermediary Sales Charge Variations in the Fund's Prospectus. More information about these and other discounts is available from your financial intermediary and in Sales Charges beginning on page 24 of the Fund's Prospectus and page 21 of the Fund's Statement of Additional Information.

---

| | | | |
|:---|:---|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Shareholder Fees (fees paid directly from your investment) | Advisers Class | Class A | Class I |
| &nbsp;&nbsp;&nbsp;&nbsp;Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) |  | 2.25% |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at purchase or redemption) |  | None<sup>(1)</sup> |  |

---

<sup>(1)</sup> Class A shares purchased at net asset value in amounts of $250,000 or more are subject to a 0.25% contingent deferred sales charge if redeemed within 12 months of purchase.

---

| | | | |
|:---|:---|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Annual Fund Operating Expenses (expenses you pay each year as a percentage of the value of your investment) | Advisers Class | Class A | Class I |
| &nbsp;&nbsp;&nbsp;&nbsp;Management Fees | 0.30% | 0.30% | 0.30% |
| &nbsp;&nbsp;&nbsp;&nbsp;Distribution and Service (12b-1) Fees | 0.15% | 0.15% |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Other Expenses | <u>0.13</u>% | <u>0.13</u>% | <u>0.13</u>% |
| &nbsp;&nbsp;&nbsp;&nbsp;Total Annual Fund Operating Expenses | 0.58% | 0.58% | 0.43% |
| &nbsp;&nbsp;&nbsp;&nbsp;Expense Reimbursements<sup>(1)</sup> | <u>(0.08)</u>% | <u>(0.08)</u>% | <u>(0.08)</u>% |
| &nbsp;&nbsp;&nbsp;&nbsp;Total Annual Fund Operating Expenses After Expense Reimbursement | 0.50% | 0.50% | 0.35% |

---

<sup>(1)</sup> The administrator has agreed to reimburse the Fund's expenses to the extent that Total Annual Fund Operating Expenses exceed 0.50% for Advisers Class, 0.50% for Class A shares and 0.35% for Class I shares. This expense reimbursement will continue through August 1, 2026. Any amendment to or termination of this reimbursement would require approval of the Board of Trustees. The expense reimbursement relates to ordinary operating expenses only and does not include expenses such as: brokerage commissions, acquired fund fees and expenses of unaffiliated funds, borrowing costs (including borrowing costs of any acquired funds), taxes or litigation expenses. Amounts reimbursed may be recouped by the administrator during the same fiscal year to the extent actual expenses are less than any contractual expense cap in place during such year. Pursuant to this arrangement, the administrator may recoup from the Fund any reimbursed expenses during the same fiscal year if such recoupment does not cause the Fund's Total Annual Operating Expenses after such recoupment to exceed (i) the expense limit in effect at the time of reimbursement; or (ii) the expense limit in effect at the time of recoupment.

**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 in the Fund 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, that the operating expenses remain the same and that any expense reimbursement arrangement remains in place for the contractual period. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

---

| | | | | |
|:---|:---|:---|:---|:---|
| | 1 Year | 3 Years | 5 Years | 10 Years |
| &nbsp;&nbsp;&nbsp;&nbsp;Advisers Class shares | $51 | $178 | $316 | $718 |
| &nbsp;&nbsp;&nbsp;&nbsp;Class A shares | $275 | $399 | $534 | $927 |
| &nbsp;&nbsp;&nbsp;&nbsp;Class I shares | $36 | $130 | $233 | $534 |

---

**Portfolio Turnover**

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" the 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 119% of the average value of its portfolio.

**Principal Investment Strategies**

Under normal market circumstances, the Fund invests at least 80% of its net assets (plus any borrowings for investment purposes) in municipal obligations that are exempt from regular federal income tax (the "Tax-Exempt 80% Policy"). At least 75% of the Fund's net assets normally will be invested in municipal obligations rated at least investment grade at the time of investment (which are those rated Baa or higher by Moody's Investors Service, Inc. ("Moody's"), or BBB or higher by either S&P Global Ratings ("S&P") or Fitch Ratings ("Fitch")) or, if unrated, determined by the investment adviser to be of at least investment grade quality. The balance of net assets may be invested in municipal obligations rated below investment grade and in unrated municipal obligations considered to be of comparable quality by the investment adviser ("junk bonds"). The Fund will not invest more than 10% of its net assets in obligations rated below B by Moody's, S&P or Fitch, or in unrated obligations considered to be of comparable quality by the investment adviser. For purposes of rating restrictions, if securities are rated differently by two or more rating agencies, the highest rating is used.

Under normal circumstances, the Fund's dollar-weighted average maturity will be less than two years. *The Fund is not a money market fund and does not seek to maintain a stable net asset value*.

The Fund may invest up to 20% of its net assets in other debt obligations, including (but not limited to) taxable municipal obligations, U.S. Treasury securities and obligations of the U.S. Government, its agencies or instrumentalities. The Fund may purchase or sell derivative instruments (such as residual interest bonds, futures contracts and options thereon, interest rate swaps, total return swaps and forward rate agreements) for hedging purposes, to seek total return or as a substitute for the purchase or sale of securities. Except as required by applicable regulation, there is no stated limit on the Fund's use of derivatives for such purposes. The Fund may invest 25% or more of its total assets in certain types of municipal obligations (such as general obligations, municipal leases, principal only municipal investments, revenue bonds and industrial development bonds) and in one or more states, territories and economic sectors (such as education, transportation, housing, hospitals, healthcare facilities or utilities). The Fund may invest in pooled investment vehicles and exchange-traded funds ("ETFs"), a type of pooled investment vehicle, to seek exposure to the municipal markets or municipal market sectors. The Fund may invest in restricted securities.

The investment adviser's process for selecting obligations for purchase and sale emphasizes the creditworthiness of the issuer or other person obligated to repay the obligation and the relative value of the obligation in the market. In evaluating creditworthiness, the investment adviser considers ratings assigned by rating agencies and generally performs additional credit and investment analysis. When deemed by the investment adviser to be relevant to its evaluation of creditworthiness and when applicable information is available, the investment adviser considers environmental, social and/or governance issues (referred to as ESG) which may impact the prospects of an issuer (or obligor) or financial performance of an obligation. When considered, one or more ESG issues are taken into account alongside other factors in the investment decision-making process and are not the sole determinant of whether an investment can be made or will remain in the Fund's portfolio. The portfolio managers also may trade securities to minimize taxable capital gains to shareholders. The Fund expects up to 25% of its annual distributions to be subject to the federal alternative minimum tax. *The Fund may not be suitable for investors subject to the federal alternative minimum tax.*

**Principal Risks**

**Market Risk.** The value of investments held by the Fund may increase or decrease in response to social, economic, political, financial, public health crises or other disruptive events (whether real, expected or perceived) in the U.S. and global markets and include events such as war, natural disasters, epidemics and pandemics, terrorism, conflicts and social unrest. These events may negatively impact broad segments of businesses and populations and may exacerbate pre-existing risks to the Fund. The frequency and magnitude of resulting changes in the value of the Fund's investments cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in reaction to changing market conditions. Monetary and/or fiscal actions taken by U.S. or foreign governments to stimulate or stabilize the global economy may not be effective and could lead to high market volatility. No active trading market may exist for certain investments held by the Fund, which may impair the ability of the Fund to sell or to realize the current valuation of such investments in the event of the need to liquidate such assets.

Eaton Vance National Ultra-Short Municipal Income Fund 2 Summary Prospectus dated August 1, 2025

**Municipal Obligations Risk.** Because the Fund may invest in municipal obligations, the Fund may be susceptible to political, legislative, economic, regulatory, tax or other factors affecting issuers of these municipal obligations, such as state and local governments and their agencies. To the extent that the Fund invests in municipal obligations of issuers in the same state, U.S. territory, or economic sector, it could be more sensitive to economic, business or political developments that affect such state or sector. Municipal obligations and their issuers may be more susceptible to downgrade, loss of revenue, default and bankruptcy during periods of economic stress. The amount of public information available about municipal obligations is generally less than for corporate equities or bonds, meaning that the investment performance of municipal obligations may be more dependent on the analytical abilities of the investment adviser than stock or corporate bond investments. The secondary market for municipal obligations 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 municipal obligations at attractive prices. The differences between the price at which an obligation can be purchased and the price at which it can be sold may widen during periods of market distress. Less liquid obligations can become more difficult to value and be subject to erratic price movements.

**Interest Rate Risk.** In general, the value of income securities will fluctuate based on changes in interest rates. The value of these securities is likely to increase when interest rates fall and decline when interest rates rise. Duration measures the time-weighted expected cash flows of a fixed-income security, while maturity refers to the amount of time until a fixed-income security matures. Generally, securities with longer durations or maturities are more sensitive to changes in interest rates than securities with shorter durations or maturities, causing them to be more volatile. Conversely, fixed-income securities with shorter durations or maturities will be less volatile but may provide lower returns than fixed-income securities with longer durations or maturities. Because the Fund is managed toward an income objective, it may hold more longer duration or maturity obligations and thereby be more exposed to interest rate risk than municipal income funds that are managed with a greater emphasis on total return. The Fund may own individual investments that have longer durations than the average duration of the Fund. In a rising interest rate environment, the duration of income securities that have the ability to be prepaid or called by the issuer may be extended. In a declining interest rate environment, the proceeds from prepaid or maturing instruments may have to be reinvested at a lower interest rate.

**Credit Risk.** Investments in municipal obligations and other debt obligations (referred to below as "debt instruments") are subject to the risk of non-payment of scheduled principal and interest. Changes in economic conditions or other circumstances may reduce the capacity of the party obligated to make principal and interest payments on such instruments and may lead to defaults. Such non-payments and defaults may reduce the value of Fund shares and income distributions. The value of debt instruments also may decline because of concerns about the issuer's ability to make principal and interest payments. In addition, the credit ratings of debt instruments may be lowered if the financial condition of the party obligated to make payments with respect to such instruments deteriorates. In order to enforce its rights in the event of a default, bankruptcy or similar situation, the Fund may be required to retain legal or similar counsel, which may increase the Fund's operating expenses and adversely affect net asset value. Municipal obligations may be insured as to principal and interest payments. If the claims-paying ability or other rating of the insurer is downgraded by a rating agency, the value of such obligations may be negatively affected.

**Lower Rated Investments Risk.** Investments rated below investment grade and comparable unrated investments (sometimes referred to as "junk") are speculative because of increased credit risk relative to other fixed income investments. Changes in economic conditions or other circumstances typically have a greater effect on the ability of issuers of lower rated investments to make principal and interest payments than they do on issuers of higher rated investments. An economic downturn generally leads to a higher non-payment rate, and a lower rated investment may lose significant value before a default occurs. Lower rated investments typically are subject to greater price volatility and illiquidity than higher rated investments.

**Derivatives Risk.** The Fund's exposure to derivatives involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other investments. The use of derivatives can lead to losses because of adverse movements in the price or value of the security, instrument, index, currency, commodity, economic indicator or event underlying a derivative ("reference instrument"), due to failure of a counterparty or due to tax or regulatory constraints. Derivatives may create leverage in the Fund, which represents a non-cash exposure to the underlying reference instrument. Leverage can increase both the risk and return potential of the Fund. Derivatives risk may be more significant when derivatives are used to enhance return or as a substitute for a cash investment position, rather than solely to hedge the risk of a position held by the Fund. Use of derivatives involves the exercise of specialized skill and judgment, and a transaction may be unsuccessful in whole or in part because of market behavior or unexpected events. Changes in the value of a derivative (including one used for hedging) may not correlate perfectly with the underlying reference instrument. Derivative instruments traded in over-the-counter markets may be difficult to value, may be illiquid, and may be subject to wide swings in valuation caused by changes in the value of the underlying reference instrument. If a derivative's counterparty is unable to honor its commitments, the value of Fund shares may decline and the Fund could experience delays in (or be unable to achieve) the return of collateral or other assets held by the counterparty. The loss on derivative transactions may substantially exceed the initial investment. A derivative investment also involves the risks relating to the reference instrument underlying the investment.

Eaton Vance National Ultra-Short Municipal Income Fund 3 Summary Prospectus dated August 1, 2025

**Leverage Risk.** Certain Fund transactions may give rise to leverage. Leverage can result from a non-cash exposure to an underlying reference instrument. Leverage can also result from borrowings or participation in residual interest bond transactions. Leverage can increase both the risk and return potential of the Fund. The use of leverage may cause the Fund to maintain liquid assets or liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations. Leverage may cause the Fund's share price to be more volatile than if it had not been leveraged, as certain types of leverage may exaggerate the effect of any increase or decrease in the value of the Fund's portfolio securities. The Fund may not be able to adjust its use of leverage rapidly enough to respond to interest rate volatility, inflation, and other changing market conditions. As a result, the Fund's use of leverage may have a negative impact on the Fund's performance from time to time. The loss on leveraged investments may substantially exceed the initial investment.

**Risk of Residual Interest Bonds.** The Fund may enter into residual interest bond transactions, which expose the Fund to leverage and greater risk than an investment in a fixed-rate municipal bond, including the risk of loss of principal. The interest payments that the Fund receives on the residual interest bonds acquired in such transactions vary inversely with short-term interest rates, normally decreasing when short-term rates increase. As such, residual interest bonds tend to underperform the market for fixed rate bonds in rising long-term interest rate environments. The value and income of, and market for, residual interest bonds are volatile, and such bonds may have limited liquidity. As required by applicable accounting standards, the Fund records interest expense as a liability with respect to floating-rate notes and also records offsetting interest income in an amount equal to this expense.

**Restricted Securities Risk.** Unless registered for sale to the public under applicable federal securities law, restricted securities can be sold only in private transactions to qualified purchasers pursuant to an exemption from registration. The sale price realized from a private transaction could be less than the Fund's purchase price for the restricted security. It may be difficult to identify a qualified purchaser for a restricted security held by the Fund and such security could be deemed illiquid. It may also be more difficult to value such securities.

**Tax-Sensitive Investing Risk.** The Fund may hold a security in order to achieve more favorable tax-treatment or sell a security in order to create tax losses. The Fund's utilization of various tax-management techniques may be curtailed or eliminated by tax legislation, regulation or interpretations. The Fund may not be able to minimize taxable distributions to shareholders and a portion of the Fund's distributions may be taxable.

**Liquidity Risk.** The Fund is exposed to liquidity risk when trading volume, lack of a market maker or trading partner, large position size, market conditions, or legal restrictions impair its ability to sell particular investments or to sell them at advantageous market prices. Consequently, the Fund may have to accept a lower price to sell an investment or continue to hold it or keep the position open, sell other investments to raise cash or abandon an investment opportunity, any of which could have a negative effect on the Fund's performance. These effects may be exacerbated during times of financial or political stress.

**Risks of Principal Only Investments.** Principal only investments entitle the Fund to receive the stated value of such investment when held to maturity. The values of principal only investments are subject to greater fluctuation in response to changes in market interest rates than obligations that pay interest currently. The Fund will accrue income on these investments and distribute that income each year. The Fund may be required to sell other investments to obtain cash needed for such income distributions.

**Pooled Investment Vehicles Risk.** Pooled investment vehicles are open- and closed-end investment companies and exchange-traded funds ("ETFs"). Pooled investment vehicles are subject to the risks of investing in the underlying securities or other investments. Shares of closed-end investment companies and ETFs may trade at a premium or discount to net asset value and are subject to secondary market trading risks. In addition, the Fund will bear a pro rata portion of the operating expenses of a pooled investment vehicle in which it invests.

Eaton Vance National Ultra-Short Municipal Income Fund 4 Summary Prospectus dated August 1, 2025

**U.S. Government Securities Risk.** Different types of U.S. government securities are subject to different levels of credit risk, including the risk of default, depending on the nature of the particular government support for that security. Although certain U.S. Government-sponsored agencies (such as the Federal Home Loan Mortgage Corporation and the Federal National Mortgage Association) may be chartered or sponsored by acts of Congress, their securities are neither issued nor guaranteed by the U.S. Treasury. With respect to U.S. government securities that are not backed by the full faith and credit of the United States, there is a risk that the U.S. Government will not provide financial support to such U.S. government agencies, instrumentalities or sponsored enterprises if not obligated to do so by law. U.S. Treasury and U.S. Government agency securities generally have a lower return than other obligations because of their higher credit quality and market liquidity.

**Tax Risk.** Income from tax-exempt municipal obligations could be declared taxable because of changes in tax laws, adverse interpretations by the relevant taxing authority or the non-compliant conduct of the issuer of an obligation.

**Portfolio Turnover Risk.** The annual portfolio turnover rate of the Fund may exceed 100%. A mutual fund with a high turnover rate (100% or more) may generate more capital gains and may involve greater expenses (which may reduce return) than a fund with a lower rate. Capital gains distributions will be made to shareholders if offsetting capital loss carry forwards do not exist.

**Risks Associated with Active Management.** The success of the Fund's investment strategy depends on portfolio management's successful application of analytical skills and investment judgment. Active management involves subjective decisions and there is no guarantee that such decisions will produce the desired results or expected returns.

**Sector and Geographic Risk.** Because the Fund may invest a significant portion of its assets in obligations issued in one or more states and/or U.S. territories and in certain types of municipal obligations and/or in certain sectors, the value of Fund shares may be affected by events that adversely affect a state, U.S. territory, sector or type of obligation and may fluctuate more than that of a more broadly diversified fund. General obligation bonds issued by municipalities can be adversely affected by economic downturns and the resulting decline in tax revenues. Revenue bonds can be adversely affected by the negative economic viability of the facility or revenue source.

**General Fund Investing Risks.** The Fund is not a complete investment program and there is no guarantee that the Fund will achieve its investment objective. It is possible to lose money by investing in the Fund. The Fund is not suited for short-term trading, and investors in the Fund should be able to tolerate potentially sharp declines in value over time. Purchase and redemption activities by Fund shareholders may impact the management of the Fund and its ability to achieve its investment objective(s). In addition, the redemption by one or more large shareholders or groups of shareholders of their holdings in the Fund could have an adverse impact on the remaining shareholders in the Fund. The Fund relies on various service providers, including the investment adviser and sub-adviser, if applicable, in its operations and is susceptible to operational, information security and related events (such as public health crises, cyber or hacking attacks) that may affect the service providers or the services that they provide to the Fund. An investment in the Fund is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Eaton Vance National Ultra-Short Municipal Income Fund 5 Summary Prospectus dated August 1, 2025

**Performance**

The following bar chart and table provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and how the Fund's average annual returns over time compare with those of one or more indexes intended to measure broad market performance. The Fund's primary benchmark index was changed from the Bloomberg 1 Year Municipal Bond Index to the Bloomberg Municipal Bond Index effective May 1, 2024 to comply with the regulation that requires the Fund's primary benchmark to represent the overall applicable market. The additional index(es) in the table provide a means to compare the Fund's average annual returns to a benchmark that the investment adviser believes is representative of the Fund's investment universe. The returns in the bar chart are for Class A shares and do not reflect a sales charge. If the sales charge was reflected, the returns would be lower. Past performance (both before and after taxes) is not necessarily an indication of how the Fund will perform in the future. The Fund's performance for certain periods reflects the effects of expense reductions. Absent these reductions, performance for certain periods would have been lower. Updated Fund performance information can be obtained by visiting www.eatonvance.com.

![](itnusmifsp_002.jpg)

For the ten years ended December 31, 2024, the highest quarterly total return for Class A was 1.34% for the quarter ended December 31, 2023, and the lowest quarterly return was -0.71% for the quarter ended June 30, 2020. The year-to-date total return through the end of the most recent calendar quarter (December 31, 2024 to June 30, 2025) was 1.51%.

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| | | | |
|:---|:---|:---|:---|
| &nbsp;&nbsp;&nbsp;&nbsp;Average Annual Total Return as of December 31, 2024 | One Year | Five Years | Ten Years |
| &nbsp;&nbsp;&nbsp;&nbsp;Advisers Class Return Before Taxes | 3.11% | 1.36% | 1.10% |
| &nbsp;&nbsp;&nbsp;&nbsp;Class A Return Before Taxes | 0.94% | 0.91% | 0.88% |
| &nbsp;&nbsp;&nbsp;&nbsp;Class A Return After Taxes on Distributions | 0.90% | 0.89% | 0.86% |
| &nbsp;&nbsp;&nbsp;&nbsp;Class A Return After Taxes on Distributions and Sale of Class A Shares | 1.84% | 1.04% | 0.95% |
| &nbsp;&nbsp;&nbsp;&nbsp;Class I Return Before Taxes | 3.27% | 1.52% | 1.26% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bloomberg Municipal Bond Index (reflects no deduction for fees, expenses or taxes) | 1.05% | 0.99% | 2.25% |
| &nbsp;&nbsp;&nbsp;&nbsp;Bloomberg 1 Year Municipal Bond Index (reflects no deduction for fees, expenses or taxes) | 2.71% | 1.39% | 1.30% |

---

These returns reflect the maximum current sales charge for Class A (2.25%). Advisers Class performance shown above for the period prior to November 20, 2020 (commencement of operations) is the performance of Class A shares at net asset value without adjustment for any differences in the expenses of the two classes. If adjusted for such differences, returns would be different. Effective January 1, 2022, the Fund changed its name and investment strategy to no longer require it to invest at least 80% of its total assets in (i) municipal floating-rate bonds or obligations and (ii) fixed-rate municipal obligations with respect to which the Fund enters into agreements to swap the fixed rate for a floating rate (the "Floating Rate 80% Policy"). The Floating-Rate 80% Policy was in effect since August 19, 2013 and, at that time, the Fund also changed its objective. Investors cannot invest directly in an Index.

BLOOMBERG<sup>®</sup> is a trademark and service mark of Bloomberg Finance L.P. and its affiliates (collectively "Bloomberg"). BARCLAYS<sup>®</sup> is a trademark and service mark of Barclays Bank Plc (collectively with its affiliates, "Barclays"), used under license. Bloomberg or Bloomberg's licensors, including Barclays, own all proprietary rights in the Bloomberg Barclays Indices. Neither Bloomberg nor Barclays is affiliated with BMR, and neither approves, endorses, reviews or recommends the Fund. Neither Bloomberg nor Barclays guarantees the timeliness, accurateness or completeness of any data or information relating to Bloomberg Municipal Bond Index and Bloomberg 1 Year Municipal Bond Index, and neither shall be liable in any way to BMR, investors in the Fund or other third parties in respect of the use or accuracy of Bloomberg Municipal Bond Index and Bloomberg 1 Year Municipal Bond Index or any data included therein.

After-tax returns are calculated using the highest historical individual U.S. federal income tax rate and do not reflect the impact of state and local taxes. Actual after-tax returns depend on a shareholder's tax situation and the actual characterization of distributions, and may differ from those shown. After-tax returns are not relevant to shareholders who hold shares in tax-deferred accounts or to shares held by non-taxable entities.After-tax returns for other Classes of shares will vary from the after-tax returns presented for Class A shares. Return After Taxes on Distributions for a period may be the same as Return Before Taxes for that period because no taxable distributions were made during that period. Also, Return After Taxes on Distributions and Sale of Fund Shares for a period may be greater than or equal to Return Before Taxes and/or Return After Taxes on Distributions for the same period because of losses realized on the sale of Fund shares.

Eaton Vance National Ultra-Short Municipal Income Fund 6 Summary Prospectus dated August 1, 2025

**Management**

**Investment Adviser.** Boston Management and Research ("BMR").

**Portfolio Managers**

**Craig R. Brandon, CFA,** Managing Director of Morgan Stanley and Vice President of BMR, has managed the Fund since September 13, 2004.

**Julie P. Callahan, CFA,** Managing Director of Morgan Stanley and Vice President of BMR, has managed the Fund since October 1, 2021.

**Purchase and Sale of Fund Shares**

You may purchase, redeem or exchange Fund shares on any business day, which is any day the New York Stock Exchange is open for business. You may purchase, redeem or exchange Fund shares either through your financial intermediary or directly from the Fund either by writing to the Fund, P.O. Box 534439, Pittsburgh, PA 15253-4439, or by calling 1-800-262-1122. The minimum initial purchase or exchange into the Fund is $1,000 for each Class (with the exception of Class I) and $1,000,000 for Class I (waived in certain circumstances). There is no minimum for subsequent investments.

**Tax Information**

The Fund's distributions are expected to primarily be exempt from regular U.S. federal income tax. However, the Fund may also distribute taxable income to the extent that it invests in taxable municipal obligations or other obligations which generate taxable income, and a portion of the Fund's distributions may be subject to the U.S. federal alternative minimum tax for shareholders subject to such tax. Distributions of any net realized gains are expected to be taxable.

**Payments to Broker-Dealers and Other Financial Intermediaries**

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

4681 8.1.25© 2025 Eaton Vance Management

Eaton Vance National Ultra-Short Municipal Income Fund 7 Summary Prospectus dated August 1, 2025