Important Notice Regarding Change in Name and Investment Policy

EATON VANCE FLOATING-RATE MUNICIPAL INCOME FUND

Supplement to Summary Prospectus dated August 1, 2021

The following changes are effective January 1, 2022:

The following replaces “Principal Investment Strategies” in “Fund Summary”:

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 average effective 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. There is no stated limit on the Fund’s use of derivatives. 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 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 managers may also consider financially material environmental, social and governance factors in evaluating an issuer. These considerations may be taken into account alongside other factors in the investment selection process. 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.