Fam. Code, § 17500

(a) In carrying out its obligations under Title IV-D of the Social Security Act (42 U.S.C. Sec. 651 et seq.), the department and the local child support agency shall have the responsibility for promptly and effectively collecting and enforcing child support obligations.

(b) The department and the local child support agency are the public agencies responsible for administering wage withholding for the purposes of Title IV-D of the Social Security Act (42 U.S.C. Sec. 651 et seq.).

(c) Except as provided in Section 17450, the local child support agency shall submit child support delinquencies to the department for purposes of supplementing the collection efforts of the local child support agencies. Submissions shall be in the form and manner and at the time prescribed by the department. Collection shall be made by the department in accordance with Section 17450. For purposes of this subdivision, “child support delinquency” means an arrearage or otherwise past due amount that accrues when an obligor fails to make any court-ordered support payment when due, which is more than 60 days past due, and the aggregate amount of which exceeds one hundred dollars ($100).

(d) If a child support delinquency exists at the time a case is opened by the local child support agency, the responsibility for the collection of the child support delinquency shall be submitted to the department no later than 30 days after receipt of the case by the local child support agency.