(a) Interest accrual. (1) Interest will accrue on any principal portion of the set-aside installment at the same rate charged on the balance of the loan.

(2) If the borrower's set-aside installment is for a loan with a limited resource rate and the Agency modifies that limited resource rate, the interest rate on the set-aside portion will be modified concurrently.

(b) Due date. The amount set-aside, including interest accrued on the principal portion of the set-aside, is due on or before the final due date of the loan.

(c) Applying payments. The Agency will apply borrower payments toward set-aside installments first to interest and then to principal.