Summary Prospectus dated December 1, 2019

Eaton Vance Municipal Opportunities Fund

Class /Ticker    A / EMOAX     C / EMOCX     I / EMOIX

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 December 1, 2019, 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.

Important Note. Beginning on January 1, 2021, as permitted by regulations adopted by the Securities and Exchange Commission, paper copies of the Fund’s annual and semi-annual shareholder reports will no longer be sent by mail unless you specifically request paper copies of the reports. Instead, the reports will be made available on the Fund’s website (http://www.eatonvance.com/funddocuments), and you will be notified by mail each time a report is posted and provided with a website address to access the report.

If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. If you are a direct investor, you may elect to receive shareholder reports and other communications from the Fund electronically by signing up for e-Delivery at eatonvance.com/edelivery. If you own your shares through a financial intermediary (such as a broker-dealer or bank), you must contact your financial intermediary to sign up.

You may elect to receive all future Fund shareholder reports in paper free of charge. If you are a direct investor, you can inform the Fund that you wish to continue receiving paper copies of your shareholder reports by calling 1-800-262-1122. If you own these shares through a financial intermediary, you must contact your financial intermediary or follow instructions included with this disclosure, if applicable, to elect to continue to receive paper copies of your shareholder reports. Your election to receive reports in paper will apply to all Eaton Vance funds held directly or to all funds held through your financial intermediary, as applicable.

Investment Objective

The Fund's investment objective is to seek to maximize after-tax total return.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. Investors may also pay commissions or other fees to their financial intermediary when they buy and hold shares of the Fund, 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 $50,000 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 52 of the Fund's Prospectus and page 22 of the Fund’s Statement of Additional Information.

Shareholder Fees (fees paid directly from your investment)	Class A	Class C	Class I
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	4.75%	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of net asset value at time of purchase or redemption)	None	1.00%	None

Annual Fund Operating Expenses (expenses you pay each year as a percentage of the value of your investment)	Class A	Class C	Class I
Management Fees	0.58%	0.58%	0.58%
Distribution and Service (12b-1) Fees	0.25%	1.00%	None
Acquired Fund Fees and Expenses	0.02%	0.02%	0.02%
Other Expenses	0.11%	0.11%	0.11%
Total Annual Fund Operating Expenses	0.96%	1.71%	0.71%

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:

	Expenses with Redemption				Expenses without Redemption
	1 Year	3 Years	5 Years	10 Years	1 Year	3 Years	5 Years	10 Years
Class A shares	$568	$766	$981	$1,597	$568	$766	$981	$1,597
Class C shares	$274	$539	$928	$2,019	$174	$539	$928	$2,019
Class I shares	$73	$227	$395	$883	$73	$227	$395	$883

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 34% 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, the interest on which is exempt from regular federal income tax (the “80% Policy”). The Fund may invest without limit in obligations the income from which is subject to the federal alternative minimum tax. The Fund has a flexible investment strategy and may invest in obligations of any duration and credit quality. The Fund also may invest up to 50% of its net assets in obligations rated below investment grade (“junk bonds”). Below investment grade obligations are those obligations rated below Baa by Moody’s Investors Service, Inc. (“Moody’s”), or below BBB by either S&P Global Ratings (“S&P”) or Fitch Ratings (“Fitch”). For the purposes of rating restrictions, if securities are rated differently by two or more rating agencies, the highest rating is used. 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 and instrumentalities (“Agency Securities”).

The Fund may purchase derivative instruments, which derive their value from another instrument, security or index. The Fund may purchase or sell various kinds of residual interest bonds, financial futures contracts and options thereon to hedge against changes in interest rates or as a substitute for the purchase of portfolio securities. The Fund also may enter into interest rate swaps, forward rate contracts and credit derivatives, which may include credit default swaps, total return swaps or credit options, as well as purchase an instrument that has greater or lesser credit risk than the municipal bonds underlying the instrument. There is no stated limit on the Fund’s use of derivatives.

In pursuing its investment objective, the Fund may acquire municipal obligations with varying maturities. Depending on the Fund’s average maturity, the interest rate risk described below may be more or less significant for the Fund. The longer the Fund’s average maturity, the more significant interest rate risk will be for the Fund. 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 sectors (such as housing, hospitals, healthcare facilities or utilities). The Fund may invest in pooled investment vehicles, including exchange-traded funds (“ETFs”), in order 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. The portfolio manager may also consider financially material environmental, social and governance factors when evaluating an issuer. These considerations may be taken into account alongside other factors in the investment selection process. The portfolio managers generally will seek to enhance after-tax total return by balancing investment considerations and tax considerations. The Fund expects to actively engage in relative value trading to take advantage of price appreciation opportunities or to realize capital losses. A portion of the Fund’s distributions generally will be subject to the federal alternative minimum tax. The Fund may not be suitable for investors subject to the federal alternative minimum tax.

Eaton Vance Municipal Opportunities Fund 2 Summary Prospectus dated December 1, 2019

Principal Risks

Market Risk. The value of investments held by the Fund may increase or decrease in response to economic, political and financial events (whether real, expected or perceived) in the U.S. and global markets. The frequency and magnitude of such changes in value 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. Actions taken by the U.S. Federal Reserve or foreign central banks to stimulate or stabilize economic growth, such as decreases or increases in short-term interest rates, could cause high volatility in markets. No active trading market may exist for certain investments, 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. Fixed-income markets may experience periods of relatively high volatility in an environment where U.S. treasury yields are rising.

Municipal Obligation Risk. 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. The increased presence of nontraditional participants (such as proprietary trading desks of investment banks and hedge funds) or the absence of traditional participants (such as individuals, insurance companies, banks and life insurance companies) in the municipal markets may lead to greater volatility in the markets because non-traditional participants may trade more frequently or in greater volume.

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. 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. Certain instruments held by the Fund pay an interest rate based on the London Interbank Offered Rate (“LIBOR”), which is the average offered rate for various maturities of short-term loans between certain major international banks. LIBOR is expected to be phased out by the end of 2021. While the effect of the phase out cannot yet be determined, it may result in, among other things, increased volatility or illiquidity in markets for instruments based on LIBOR and changes in the value of such instruments.

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.

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 or other 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 fund that invests more broadly. General obligation bonds issued by municipalities are adversely affected by economic downturns and any resulting decline in tax revenues. Please refer to the Fund's Statement of Additional Information for state-specific economic information as well as information about Puerto Rico, the U.S. Virgin Islands, Guam and American Samoa.

Eaton Vance Municipal Opportunities Fund 3 Summary Prospectus dated December 1, 2019

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 the return of collateral or other assets held by the counterparty. The loss on derivative transactions may substantially exceed the initial investment, particularly when there is no stated limit on the Fund’s use of derivatives. A derivative investment also involves the risks relating to the reference instrument underlying the investment.

Borrowing Risk. Borrowing cash to increase investments (sometimes referred to as “leverage”) may exaggerate the effect on the Fund’s net asset value of any increase or decrease in the value of the security purchased with the borrowings. Successful use of a borrowing strategy depends on the investment adviser’s ability to predict correctly interest rates and market movements. There can be no assurance that the use of borrowings will be successful. In connection with its borrowings, the Fund will be required to maintain specified asset coverage with respect to such borrowings by applicable federal securities laws and the terms of its credit facility with the lender. The Fund may be required to dispose of portfolio investments on unfavorable terms if market fluctuations or other factors cause the required asset coverage to be less than the prescribed amount. Borrowings involve additional expense to the Fund.

Leverage Risk. Certain Fund transactions may give rise to leverage. Leverage can result from a non-cash exposure to an asset, index, rate or instrument. Leverage can increase both the risk and return potential of the Fund. The Fund is required to segregate liquid assets or otherwise cover the Fund’s obligation created by a transaction that may give rise to leverage. The use of leverage may cause the Fund to liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations or to meet segregation requirements. 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 loss on leveraged investments may substantially exceed the initial investment.

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.

Lower Rated Investments Risk. Investments rated below investment grade and comparable unrated investments (sometimes referred to as “junk”) have speculative characteristics because of the credit risk associated with their issuers. 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.

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. 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. The value 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.

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.

Eaton Vance Municipal Opportunities Fund 4 Summary Prospectus dated December 1, 2019

U.S. Government Securities Risk. 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. U.S. Treasury securities generally have a lower return than other obligations because of their higher credit quality and market liquidity.

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.

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 to 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.

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.

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.

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 designed to be a long-term investment vehicle and is not suited for short-term trading. Investors in the Fund should have a long-term investment perspective and be able to tolerate potentially sharp declines in value. 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, in its operations and is susceptible to operational, information security and related events (such as 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.

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 a broad-based securities market index. 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.

During the period from December 31, 2011 through December 31, 2018, the highest quarterly total return for Class A was 5.37% for the quarter ended March 31, 2014, and the lowest quarterly return was -5.03% for the quarter ended June, 30, 2013. The year-to-date total return through the end of the most recent calendar quarter (December 31, 2018 to September 30, 2019) was 5.95%.

Eaton Vance Municipal Opportunities Fund 5 Summary Prospectus dated December 1, 2019

Average Annual Total Return as of December 31, 2018	One Year	Five Years	Life of Fund
Class A Return Before Taxes	-3.77%	3.96%	4.15%
Class A Return After Taxes on Distributions	-3.89%	3.80%	3.90%
Class A Return After Taxes on Distributions and the Sale of Class A Shares	-1.46%	3.47%	3.62%
Class C Return Before Taxes	-0.61%	4.25%	4.35%
Class I Return Before Taxes	1.30%	5.24%	5.11%
Bloomberg Barclays Municipal Bond Index (reflects no deduction for fees, expenses or taxes)	1.28%	3.82%	3.60%

These returns reflect the maximum sales charge for Class A (4.75%). Class A and Class I commenced operations on May 31, 2011. The Class C performance shown above for the period prior to August 18, 2014 (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. Investors cannot invest directly in an Index.

After-tax returns are calculated using the highest historical individual 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 for shareholders who hold Fund 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 the 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.

Management

Investment Adviser. Eaton Vance Management (“Eaton Vance”).

Portfolio Manager. The Fund is managed by Adam A. Weigold, Vice President of Eaton Vance, who has managed the Fund since its inception in May 2011.

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 (except for purchases of Class C shares by accounts with no specified financial intermediary) directly from the Fund either by writing to the Fund, P.O. Box 9653, Providence, RI 02940-9653, 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 $250,000 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 federal income taxes. 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, U.S. Treasury securities or Agency Securities. 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.

5097 12.1.19 © 2019 Eaton Vance Management

Eaton Vance Municipal Opportunities Fund 6 Summary Prospectus dated December 1, 2019