(A) When a court issues or modifies a court support order, the court shall determine the following:
(1) Whether the obligor is in default under a prior court support order or the court support order being modified;
(2) If the obligor is in default, the date the court support order went into default and the amount of support arrearages owed pursuant to the default.
If the court determines the obligor is in default under a support order, the court shall issue a new order requiring the obligor to pay support. If the court determines the default was willful, the court may assess interest on the arrearage amount from the date the court specifies as the date of default to the date the court issues the new order requiring the payment of support and, if interest is assessed, shall compute the interest at the rate specified in section 1343.03 of the Revised Code. The court shall specify in the support order the amount of interest the court assessed against the obligor, if any, and incorporate the amount of interest into the new monthly payment plan.
(B) When a court issues or modifies a court support order, the court may include in the support order a statement ordering either party to pay the costs of the action, including, but not limited to, attorney's fees, fees for genetic tests in contested actions under sections 3111.01 to 3111.18 of the Revised Code, and court costs.