I’m not sure if this questioned has been addressed or not for preferred rate loans. These discounted loan rates are offered for employees, automatic payments, and to those clients with a larger deposit relationship. If an employee, for example, had a 1/4% discount on the the current 10-year 3.75% rate (rate of 3.50%), under the revised Reg Z ATR rules do we underwrite to the 3.75% rate and not the discounted rate? If the rate does increase (employee resigns or automatic payment ceases), can the loan still be considered a QM?
In order to meet the QM requirements, you would use the highest rate possible in the first five years after the first payment is due, so if the non-discounted rate is a possibility (meaning the discounted rate is conditional and can revert to the non-discounted rate) you would use the non-discounted rate.
The ability to repay rules do not specifically address preferred rate loans. Robin’s reply provides a safe course of action for General Rule QMs. If you utilize one of the other ability-to-repay options the response may be different.