December 28, 2020

U.S. Securities and Exchange Commission
100 F Street, N.E.
Washington, DC 20549

Re: Vanguard Money Market Reserves (the “Trust”)
2-52698

Commissioners:

Pursuant to Rule 497(e) under the Securities Act of 1933, we hereby file exhibits containing interactive data format risk/return summary information that reflects the risk/return summary information in the supplement dated December 10, 2020, filed pursuant to Rule 497(e), for the Vanguard Cash Reserves Federal Money Market Fund, a series of the above mentioned Trust.

Please contact me at (610) 669-7310 or (lisa_k_whittaker@vanguard.com), with any questions or comments.

Sincerely,

/s/ Lisa K. Whittaker

Lisa K. Whittaker
Associate Counsel
The Vanguard Group, Inc.

Enclosures

cc: Lisa N. Larkin

U.S. Securities and Exchange Commission