California Code, Insurance Code - INS § 10123.137

(a) Each contract between a health insurer and a provider shall contain provisions requiring a fast, fair, and cost-effective dispute resolution mechanism under which providers may submit disputes to the insurer, and requiring the insurer to inform its providers, upon contracting with the insurer, or upon change to these provisions, of the procedures for processing and resolving disputes, including the location and telephone number where information regarding disputes may be submitted.

(b) An insurer shall also ensure that a dispute resolution mechanism is accessible to noncontracting providers for the purpose of resolving billing and claims disputes.

(c) Disputes are to be submitted to the insurer in writing and shall include provider name, provider tax identification number, patient name, insurer's identification information, dates of service, description of dispute, and, if applicable, billed and paid amounts. The insurer shall resolve each provider dispute consistent with applicable law and issue a written determination within 45 working days after the date of receipt of the provider dispute.

(d) On and after July 1, 2007, an insurer shall annually submit a report to the department regarding its dispute resolution mechanism. The report shall be public information and include, at a minimum, information on the number of providers that utilized the dispute resolution mechanism and a summary of the disposition of those disputes. To the extent the commissioner requires detailed information disclosing emerging or established patterns of provider disputes or corrective action by the insurer, the commissioner may maintain the confidentiality of any information found to be proprietary, upon written request of the insurer. In no event shall the commissioner find the required minimum information described in this subdivision to be proprietary.

(e) If an insurer has an affiliated or subsidiary company that is licensed as a health care service plan under Chapter 2.2 (commencing with Section 1340) of Division 2 of the Health and Safety Code, the insurer may use the same procedures relating to the provider dispute resolution process established by the affiliated or subsidiary entity pursuant to subdivision (h) of Section 1367 of the Health and Safety Code.