March 10, 1998
Securities and Exchange Commission
Judiciary Plaza
450 Fifth Street, N.W.
Washington, D.C.
Re: Calvert Social Investment Fund - Managed Index Portfolio
2-75106 and 811-3334
In lieu of filing under paragraph (b) or (c) of Section 497, the
above registrant is hereby filing a certification that:
(1) the form of prospectus and statement of additional information
that would have been filed under paragraph (b) or (c) of Section 497 would not
have differed from those contained in the most recent registration statement
(effective March 3, 1998); and
(2) the text of the most recent registration statement (effective
March 3, 1998) has been filed electronically.
If you have questions or require further information, please contact
me at 301-951-4881.
Sincerely,
/s/Susan Walker Bender
Susan Walker Bender Stoner
Associate General Counsel
