Fam. Code, § 4251

(a) Commencing July 1, 1997, each superior court shall provide sufficient commissioners to hear Title IV-D child support cases filed by the local child support agency. The number of child support commissioners required in each county shall be determined by the Judicial Council as prescribed by paragraph (3) of subdivision (b) of Section 4252. All actions or proceedings filed by the local child support agency in a support action or proceeding in which enforcement services are being provided pursuant to Section 17400, for an order to establish, modify, or enforce child or spousal support, including actions to establish parentage, shall be referred for hearing to a child support commissioner unless a child support commissioner is not available due to exceptional circumstances, as prescribed by the Judicial Council pursuant to paragraph (7) of subdivision (b) of Section 4252. All actions or proceedings filed by a party other than the local child support agency to modify or enforce a support order established by the local child support agency or for which enforcement services are being provided pursuant to Section 17400 shall be referred for hearing to a child support commissioner unless a child support commissioner is not available due to exceptional circumstances, as prescribed by the Judicial Council pursuant to paragraph (7) of subdivision (b) of Section 4252.

(b) The commissioner shall act as a temporary judge unless an objection is made by the local child support agency or any other party. The Judicial Council shall develop a notice that shall be included on all forms and pleadings used to initiate a child support action or proceeding that advises the parties of their right to review by a superior court judge and how to exercise that right. The parties shall also be advised by the court prior to the commencement of the hearing that the matter is being heard by a commissioner who shall act as a temporary judge unless any party objects to the commissioner acting as a temporary judge. While acting as a temporary judge, the commissioner shall receive no compensation other than compensation as a commissioner.

(c) If a party objects to the commissioner acting as a temporary judge, the commissioner may hear the matter and make findings of fact and a recommended order. Within 10 court days, a judge shall ratify the recommended order unless either party objects to the recommended order, or where a recommended order is in error. In both cases, the judge shall issue a temporary order and schedule a hearing de novo within 10 court days. A party may waive the right to the review hearing at any time.

(d) The commissioner, where appropriate, shall do any of the following:

(1) Review and determine ex parte applications for orders and writs.

(2) Take testimony.

(3) Establish a record, evaluate evidence, and make recommendations or decisions.

(4) Enter judgments or orders based upon voluntary acknowledgments of support liability and parentage and stipulated agreements respecting the amount of child support to be paid.

(5) Enter default orders and judgments pursuant to Section 4253.

(6) In actions in which parentage is at issue, order the mother, child, and alleged father to submit to genetic tests.

(e) The commissioner shall, upon application of a party, join issues concerning custody, visitation, and protective orders in the action filed by the local child support agency, subject to Section 17404. After joinder, the commissioner shall:

(1) Refer the parents for mediation of disputed custody or visitation issues pursuant to Section 3170.

(2) Accept stipulated agreements concerning custody, visitation, and protective orders and enter orders pursuant to the agreements.

(3) Refer contested issues of custody, visitation, and protective orders to a judge or to another commissioner for hearing. A child support commissioner may hear contested custody, visitation, and restraining order issues only if the court has adopted procedures to segregate the costs of hearing Title IV-D child support issues from the costs of hearing other issues pursuant to applicable federal requirements.

(f) The local child support agency shall be served notice by the moving party of any proceeding under this section in which support is at issue. An order for support that is entered without the local child support agency having received proper notice shall be voidable upon the motion of the local child support agency.