Prospectus Certification by Investment Company (Form 497J)

111 Huntington Avenue, Boston, Massachusetts 02199

617-954-5000

April 2, 2026

VIA EDGAR

United States Securities and Exchange Commission

100 F Street, N.E.

Washington, D.C. 20549

Re: Massachusetts Investors Growth Stock Fund (the "Trust") (File Nos. 2-14677 and 811-859)

Ladies and Gentlemen:

Pursuant to Rule 497(j) under the Securities Act of 1933, as amended, please accept this letter on behalf of the Trust as certification that the Prospectus and the Statement of Additional Information for the Trust do not differ from those contained in Post-Effective Amendment No. 112 (the "Amendment") to the Trust's Registration Statement on Form N-1A. The Amendment was filed electronically on March 27, 2026.

Please call the undersigned at (617) 954-5655 or David Harris at (617) 954-4417 with any questions you may have.

Sincerely,

/s/WILLIAM B. WILSON

William B. Wilson

Assistant Vice President and Senior Counsel