Cal. Welf. & Inst. Code § 903.41

(a) It is the intention of the Legislature that the family law departments and juvenile departments of each superior court coordinate determinations of parentage and the setting of support to ensure that the State of California remains in compliance with federal regulations for child support guidelines. The Legislature therefore enacts this section for the purpose of ensuring a document exchange between the family law departments and juvenile departments of each superior court as necessary to administer the public social services administered or supervised by the State Department of Social Services.
(b) If the issue of paternity is raised during any hearings pursuant to Section 300, 601, or 602, the court clerk shall notify the local child support agency for an inquiry concerning any superior court order or judgment which addresses the issue.
1. (1) If the local child support agency determines that a judgment for parentage already exists, the local child support agency shall obtain and forward certified copies of the judgment to the juvenile court and the court shall take judicial notice thereof.
2. (2) If the local child support agency determines that the issue of parentage has not been determined, the juvenile court may determine the issue of parentage and, if it does so, shall give notice to the local child support agency.
(c) If the court establishes paternity of a minor child, the court clerk shall forward the order on a form to be adopted by the Judicial Council to the local child support agency.
(d) If a child is receiving public assistance under the CalWORKs program, or if it appears to the court that the child may receive assistance under CalWORKs, the court shall direct the clerk of the court to advise the local child support agency.
(e) The court shall advise the parent of the minor of the possibility that the local child support agency may file an action for support if the child receives CalWORKs, pursuant to Section 17402 of the Family Code.