MAINSTAY FUNDS TRUST

51 Madison Avenue

New York, NY 10010

May 9, 2023

VIA EDGAR

Filing Desk

Securities and Exchange Commission

100 F Street, N.E.

Washington, D.C. 20549

RE:      Form N-14 for MainStay PineStone U.S. Equity Fund

Dear Sir/Madam:

On behalf of MainStay Funds Trust (the “Registrant”), we are transmitting for filing with the Securities and Exchange Commission a Proxy Statement/Prospectus on Form N-14 (the “N-14”). The N-14 relates to the proposed reorganization of Fiera Capital U.S. Equity Long-Term Quality Fund, a series of Fiera Capital Series Trust, with and into MainStay PineStone U.S. Equity Fund, a series of the Registrant.

Please direct any questions concerning the filing to undersigned at (201) 685-6221 or Thomas_Humbert@nylim.com.

Very truly yours,

/s/ Thomas C. Humbert, Jr.

Thomas C. Humbert, Jr.

Assistant Secretary