This Supplement is filed pursuant to Rule 497(d) with regard to
Municipal Investment Trust Fund, Insured Series 401
The text of the supplement to the Prospectus dated November 20, 1998 is as
follows:
Supplement dated December 15, 1998
to Prospectus dated November 20, 1998, of
Municipal Investment Trust Fund
Insured Series 401
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The figures in the Example on Page 4 should be revised as follows:
If you sell your units at the end of the period:
1 Year 3 Years 5 Years 10 Years
$323 $352 $383 $476
If you do not sell your units:
1 Year 3 Years 5 Years 10 Years
$228 $352 $383 $476
