California Code, Family Code - FAM § 17526

(a) Upon request of an obligor or obligee, the local child support agency shall review the amount of arrearages alleged in a statement of arrearages that may be submitted to the local child support agency by an applicant for child support enforcement services. The local child support agency shall complete the review in the same manner and pursuant to the same timeframes as a complaint submitted pursuant to Section 17800. In the review, the local child support agency shall consider all evidence and defenses submitted by either parent on the issues of the amount of support paid or owed.

(b) The local child support agency may, in its discretion, suspend enforcement or distribution of arrearages if it believes there is a substantial probability that the result of the administrative review will result in a finding that there are no arrearages.

(c) Any party to an action involving child support enforcement services of the local child support agency may request a judicial determination of arrearages. The party may request an administrative review of the alleged arrearages prior to requesting a judicial determination of arrearages.The local child support agency shall complete the review in the same manner and pursuant to the same timeframes specified in subdivision (a). Any motion to determine arrearages filed with the court shall include a monthly breakdown showing amounts ordered and amounts paid, in addition to any other relevant information.

(d) A county that submits a claim for reimbursement as a state-mandated local program of costs incurred with respect to the administrative review of alleged child support arrearages under this section shall be ineligible for state subventions or, to the extent permitted by federal law, state-administered federal subventions, for child support in the amount of any local costs under this section.