NATIXIS FUNDS TRUST I

May 3, 2018

VIA EDGAR

U.S. Securities and Exchange Commission

100 F Street, NE

Washington, DC 20549

Re: Natixis Funds Trust I

(File Nos.: 002-98326 and 811-04323)

Dear Sir or Madam:

Pursuant to Rule 497(j) of the Securities Act of 1933, as amended, I hereby certify that the Statement of Additional Information, dated May 1, 2018, for the Loomis Sayles Multi-Asset Income Fund, Mirova Global Green Bond Fund, Mirova Global Sustainable Equity Fund, Natixis Oakmark International Fund, Natixis U.S. Equity Opportunities Fund and Vaughan Nelson Small Cap Value Fund, each a series of Natixis Funds Trust I, does not differ from that contained in Post-Effective Amendment No. 139 that was filed electronically on April 27, 2018.

Please direct any questions or comments on the enclosed materials to me at (617) 449-2818.

Very truly yours,

/s/ John DelPrete

John DelPrete

Assistant Secretary