(a) This section applies to all proceedings involving a support order, including, but not limited to, a support order establishing an order for past support or reimbursement of public assistance.

(b) The court shall direct that all payments ordered for maintenance or support be made to the public authority responsible for child support enforcement so long as the obligee is receiving or has applied for public assistance, or has applied for child support or maintenance collection services. Public authorities responsible for child support enforcement may act on behalf of other public authorities responsible for child support enforcement, including the authority to represent the legal interests of or execute documents on behalf of the other public authority in connection with the establishment, enforcement, and collection of child support, maintenance, or medical support, and collection on judgments.

(c) Payments made to the public authority must be credited as of the date the payment is received by the central collections unit, except that payments made under section 518A.53 may be considered to have been paid as of the date the obligor received the remainder of the income.

(d) Monthly amounts received by the public agency responsible for child support enforcement from the obligor that are greater than the monthly amount of public assistance granted to the obligee must be remitted to the obligee.