"Ignoring the dollar amount of the first and final payments, if ALL the disclosed payments are not equal (exactly equal) in dollar amount, then the "irregular" tolerance applies."

Following up on this post with respect to PMI. Would the same irregular transaction definition for 1/4% tolerance hold true for fixed rate FHA loans with monthly MIP? Although the amortization schedule clearly shows regular payments at 12 month intervals with declining MIP there are 30 years of differing payments for instance so would the above apply?

Yes. Unless FHA's changed in recent years, you would meet the "irregular" definition on payment #13 (or whenever the loan gets to the first MI renewal premium step-down.) In fact, ANY loan with MI is very likely irregular. Most non-FHA mortgages become irregular--if not on the date of a MI premium reduction, then on the date the loan hits automatic MI termination.

Thank you Richard!