December 1, 1995
Securities and Exchange Commission
450 Fifth Street, N.W.
Washington, D.C. 20549-1004
Attn: Filing Desk - Stop 1-4
Re: Insured Municipals Income Trust, 21st Insured Multi-Series
File No. 2-99428 CIK #773865
Ladies/Gentlemen:
In accordance with the provisions of Rule 497(j) of Regulation C
under the Securities Act of 1933 (the "Securities Act") this letter
serves to certify that the most recent amendment to the Post-Effective of
the subject Registration Statement on Form S-6 for the above captioned
Trust does not differ from that which would have been filed pursuant to
Rule 497(b) of the Securities Act. Amendment No. 10 to the Post-
Effective, which was the most recent amendment to the Post-Effective of
the Registration Statement, was filed electronically with the Commission
on November 24, 1995.
Very truly yours,
Van Kampen American Capital
Distributors, Inc.
