Important Notice Regarding Change in Name and Investment Policy

EATON VANCE SHORT DURATION REAL RETURN FUND

Supplement to Prospectus, Summary Prospectus and Statement of Additional Information dated March 1, 2017

The following changes are effective on or around October 23, 2017. These changes will not result in any changes to the Fund’s investments or investment approach.

1.  

The name of Eaton Vance Short Duration Real Return Fund is changed to Eaton Vance Short Duration Inflation-Protected Income Fund.

2.

The following replaces “Principal Investment Strategies”:

Under normal market conditions, the Fund seeks to achieve its investment objective of real return by investing at least 80% of its net assets (plus any borrowings for investment purposes) in “inflation protected” instruments, which include (i) inflation-indexed debt obligations of varying maturities issued by the United States and non-U.S. governments, their agencies or instrumentalities (such as Treasury Inflation Protected Securities, or “TIPS”), corporations and other issuers and (ii) other fixed or floating-rate debt obligations (including junior and senior loans) with respect to which the Fund enters into agreements to swap nominal interest payments for payments based on changes in the U.S. Consumer Price Index (“CPI”) or other measures of inflation (the “80% Policy”). Real return is defined as total return less the estimated cost of inflation (typically measured by the change in an official inflation measure). The Fund will limit its real duration to 3.5 years or less and will maintain a weighted average credit quality of investment grade. The Fund is “non-diversified,” which means it may invest a greater percentage of its assets in the securities of a single issuer than a “diversified” fund.

The Fund may invest up to 30% of its total assets in securities denominated in foreign currencies and may invest beyond this limit in U.S. dollar-denominated securities of foreign issuers. The Fund may invest up to 10% of its total assets in securities and instruments that are economically tied to emerging market countries. The Fund will normally limit its foreign currency exposure (from non-U.S. dollar-denominated securities or currencies) to 20% of its total assets. The Fund may invest in instruments rated below investment grade (below BBB by Moody’s Investors Service, Inc., or equivalently rated by Standard & Poor’s Ratings Services or Fitch Ratings, or, if unrated, determined by the investment adviser to be of comparable quality). The Fund may purchase and sell securities on a when-issued, delayed delivery or forward commitment basis and may invest in repurchase agreements or reverse repurchase agreements. Such instruments may be entered into for purposes of investment leverage. Forward purchases of inflation-indexed debt obligations of varying maturities issued by the United States and non-U.S. governments, their agencies or instrumentalities (such as TIPS), corporations and other issuers will be considered “inflation protected” instruments for purposes of the Fund’s 80% Policy. The Fund may invest in derivative instruments, such as swap agreements, options, futures contracts or options on futures. There is no stated limit on the Fund’s use of derivatives. The Fund also may engage in short sales, may invest in mortgage-backed securities, commercial mortgage-backed securities or asset-backed securities and is authorized to borrow for investment purposes. The Fund may, without limitation, seek to obtain market exposure to the securities in which it primarily invests by entering into a series of purchase and sale contracts or by using other investment techniques (such as dollar rolls). The Fund may invest in exchange-traded funds (“ETFs”), a type of pooled investment vehicle, in order to equitize cash positions or seek exposure to certain markets or market sectors.

The Fund generally invests directly in TIPS and certain other “inflation protected” instruments and may also invest in one or more of the following registered investment companies sponsored by the Eaton Vance organization: Eaton Vance Floating Rate Portfolio, Senior Debt Portfolio and Short-Term U.S. Government Portfolio (each, a “Portfolio”). Each Portfolio is described in “Further Information about the Portfolios” in the Fund Prospectus. The Fund’s portfolio managers, taking market and other factors into consideration, determine the percentage of the Fund’s assets to be invested directly and in each Portfolio. The Fund also may invest directly in securities or other instruments to gain exposure to sectors of the market the investment adviser believes may not be represented or are underrepresented by the Portfolios, to hedge certain Portfolios and/or to otherwise manage the exposures of the Fund

August 14, 2017 26860  8.14.17