252D.18A  Multiple income withholding orders — amounts withheld by payor.
  When the obligor is responsible for paying more than one support obligation and the payor of income has received more than one income withholding order or notice of an order for the obligor, the payor shall withhold amounts in accordance with all of the following:
  1.  The total of all amounts withheld shall not exceed the amounts specified in 15 U.S.C. §1673(b). For orders or notices issued by the child support recovery unit, the limit for the amount to be withheld shall be specified in the order or notice.
  2.  As reimbursement for the payor’s processing costs, the payor may deduct a fee of no more than two dollars for each payment withheld in addition to the amount withheld for support.
  3.  Priority shall be given to the withholding of current support rather than delinquent support. The payor shall not allocate amounts withheld in a manner which results in the failure to withhold an amount for one or more of the current support obligations.
  a.  To arrive at the amount to be withheld for each obligee, the payor shall total the amounts due for current support under the income withholding orders and the notices of orders and determine the proportionate share for each obligee. The proportionate share shall be determined by dividing the amount due for current support for each order or notice of order by the total due for current support for all orders and notices of orders. The results are the percentages of the obligor’s net income which shall be withheld for each obligee.
  b.  If, after completing the calculation in paragraph “a”, the withholding limit specified under subsection 1 has not been attained, the payor shall total the amounts due for arrearages and determine the proportionate share for each obligee. The proportionate share amounts shall be established utilizing the procedures established in paragraph “a” for current support obligations.
  4.  The payor shall identify and report payments by the obligor’s name, account number, amount, and date withheld pursuant to section 252D.17. If payments for multiple obligees are combined, the portion of the payment attributable to each obligee shall be specifically identified only if the payor is directed to do so by the child support recovery unit.
93 Acts, ch 78, §14; 96 Acts, ch 1141, §12, 13; 97 Acts, ch 175, §63, 64; 98 Acts, ch 1170, §9; 2002 Acts, ch 1018, §1, 2; 2009 Acts, ch 15, §1