February 26, 2000
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, 173rd Insured Multi-
Series
File No. 33-56945 CIK #897400
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. 5 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 February 23, 2000.
Very truly yours,
VAN KAMPEN FUNDS INC.
