California Code, Welfare and Institutions Code - WIC § 11457

(a) Money from noncustodial parents for child or spousal support with respect to whom an assignment under Section 11477 has been made shall be paid directly to the local child support agency and shall not be paid directly to the family.Absent parent support payments, when collected by or paid through any public officer or agency, shall be transmitted to the county department providing aid under this chapter until a procedure is established under subdivision (b).

(b) The Department of Child Support Services, by regulation, shall work in conjunction with the California State Association of Counties, the County Welfare Director's Association, the Child Support Director's Association, and other pertinent stakeholders to establish procedures not in conflict with federal law, for the collection and distribution of noncustodial parent support payments.

(c) If an amount collected as child or spousal support represents payment on the required support obligation for future months, the amount shall be applied to such future months. However, no such amounts shall be applied to future months unless amounts have been collected which fully satisfy the support obligation assigned under subdivision (a) of Section 11477 for the current months and all past months.