((a)) ** .—** Subject to this section, the Secretary or Administrator shall prescribe regulations to assess a fee for guaranteeing an obligation under this chapter.

((b)) ** .—**

((1)) ** .—** The amount of the fee for a guarantee under this chapter shall be equal to the sum of the amounts determined under paragraph (2) for the years in which the guarantee is in effect.

((2)) ** .—** The amount referred to in paragraph (1) for a year in which the guarantee is in effect is the present value of the amount calculated under paragraph (3). To determine the present value, the Secretary or Administrator shall apply a discount rate determined by the Secretary of the Treasury, considering current market yields on outstanding obligations of the United States Government having periods to maturity comparable to the period to maturity for the guaranteed obligation.

((3)) ** .—** The amount referred to in paragraph (2) shall be calculated by multiplying—

((A)) the estimated average unpaid principal amount of the obligation that will be outstanding during the year (excluding the average amount, other than interest, on deposit during the year in an escrow fund under ); by

((B)) the fee rate set under paragraph (4).

((4)) ** .—** To set the fee rate referred to in paragraph (3)(B), the Secretary or Administrator shall establish a formula that—

((A)) takes into account the security provided for the guaranteed obligation; and

((B)) is a sliding scale based on the creditworthiness of the obligor, using—

((i)) the lowest allowable rate under paragraph (5) for the most creditworthy obligors; and

((ii)) the highest allowable rate under paragraph (5) for the least creditworthy obligors.

((5)) ** .—** The fee rate set under paragraph (4) shall be—

((A)) for a delivered vessel or equipment, at least 0.5 percent and not more than 1 percent; and

((B)) for a vessel to be constructed, reconstructed, or reconditioned or equipment to be delivered, at least 0.25 percent and not more than 0.5 percent.

((c)) ** .—** A fee for the guarantee of an obligation under this chapter shall be collected not later than the date on which an amount is first paid on the obligation.

((d)) ** .—** A fee paid under this section is eligible to be financed under this chapter and shall be included in the actual cost of the obligation guaranteed.

((e)) ** .—** A fee paid under this section is not refundable. However, an obligor shall receive credit for the amount paid for the remaining term of the obligation if the obligation is refinanced and guaranteed under this chapter after the refinancing.