EATON VANCE SHORT DURATION INFLATION-PROTECTED INCOME FUND

Supplement to Summary Prospectus and Prospectus dated March 1, 2019

The following changes are effective December 31, 2019:

1.  The following replaces “Portfolio Managers” under “Management”:

Portfolio Managers

Jason DesLauriers, Vice President of Eaton Vance, has managed the Fund since December 2019.

Brian S. Ellis, Vice President of Eaton Vance, has managed the Fund since December 2019.

2.  The following replaces the fourth paragraph under “Management and Organization”:

For the fiscal year ended October 31, 2018, the effective annual rate of the investment advisory fees paid by the Fund (including the fee on Investable Assets and the Fund’s allocable portion of Portfolio advisory fees) to Eaton Vance was 0.45%. The Fund has been co-managed by Jason DesLauriers and Brian S. Ellis since December 2019. Mr. DesLauriers joined Eaton Vance in 2009, is currently a Vice President of Eaton Vance and BMR and is a portfolio manager for the investment grade fixed income team at Eaton Vance. Mr. Ellis is a Vice President of Eaton Vance and BMR. Prior to joining the Eaton Vance organization on December 31, 2016, he was Portfolio Manager and a member of the Taxable Fixed Income Team at Calvert Investment Management, Inc. since May 2012.

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