D.C. Mun. Regs. tit. 16, r. 16-338
The holder of an instrument of security or of a refinancing contract, upon request by the buyer, may agree to an amendment to that contract or instrument to extend the scheduled due date of all or any part of any installment or installments or to restate or reschedule the unpaid balance due under the instrument or contract.
The holder may collect for that refinanced instrument or contract a refinance charge not to exceed an amount computed as provided in §§ 338.3 through 338.5; or, in the alternative, if all or some unpaid installments are deferred for not more than three (3) months, the holder may at the holder's election charge and collect on the amount deferred for the period deferred an amount computed at a rate which does not exceed the maximum which governed the original contract; Provided, that a minimum extension charge of one dollar ($ 1) shall be permitted.
A refund credit (such as a credit for prepayment under § 337.2 ), shall be deducted from the sum of the following:
The resulting amount under § 338.3 shall constitute a principal balance. The refinance charge shall be computed for the term of the refinancing contract at a rate of finance charge which does not exceed the maximum which governed the original contract.
The twenty-five dollar ($ 25) minimum finance charge referred to in § 2(a) of Pub. L. 86-431 (74 Stat. 69) shall not apply in calculating refinance charges.
D.C. Mun. Regs. tit. 16, r. 16-338