((a)) ** .—** In carrying out work under reimbursable agreements with any State, local, or tribal government, the Secretary, without regard to any provision of law or a regulation—

((1)) may record obligations against accounts receivable from those governments; and

((2)) shall credit amounts received from those governments to the appropriate account.

((b)) ** .—** Amounts shall be credited within 90 days of the date of the original request by the Service for payment.