When a noncustodial parent has more than one case with DCS, the law tells DCS how to split up a support payment between cases. It's based on a percent-of-total basis.
Current support is paid first. If a payment does not equal the total amount owed for all the noncustodial parent's cases, DCS divides the payment proportionately. Once current support for the month is paid, DCS applies amounts over current support to back support owed.
IRS tax refund intercept payments are an exception to this rule. DCS must apply these payments first to arrears owed to the state, then arrears owed to the family. DCS may not apply IRS tax intercept payments to current support. This process will change effective with IRS payments received by DCS on or after October 1, 2008.
Back support payments are also proportioned based on a percent of total. If you received public assistance in another state that has asked DCS to collect back support, that case will receive a percent of the back support payment. When DCS is providing payment processing services only (PSO) on one of the cases, the non-custodial parent must send payments and indicate that a payment is for the PSO case only. Otherwise, DCS will apply payments proportionately to the non-PSO cases.