Exhibit 5.1
CONSENT OF INDEPENDENT ACCOUNTANTS
The Sponsors and Trustee of Municipal Investment Trust Fund--Insured
Series--403, Defined Asset Funds:
We consent to the use in this Post-Effective Amendment No. 1 to Registration
Statement No. 333-71609 of our opinion dated June 29, 2000 appearing in the
Prospectus, which is part of such Registration Statement, and to the reference
to us under the heading "How The Fund Works--Auditors" in such Prospectus.
DELOITTE & TOUCHE LLP
New York, N.Y.
July 19, 2000
