Under the Truth in Lending Act (TILA), for adjustable-rate mortgages (ARMs) like a 5/1 ARM, the MLO must calculate the borrower's monthly payment amount based on the fully indexed rate, not the introductory rate. The fully indexed rate is the sum of the index and the margin at the time of origination, reflecting the potential payment increases after the introductory period ends.
* This requirement ensures borrowers understand what their payments could be after the rate adjusts, helping them evaluate the true affordability of the loan.
References:
* Truth in Lending Act (TILA), 12 CFR Part 1026 (Regulation Z)
* CFPB ARM Guidelines