California Code, Labor Code - LAB § 3823

(a) The administrative director, in coordination with the Bureau of Fraudulent Claims of the Department of Insurance, the Medi-Cal Fraud Task Force, and the Division of Medi-Cal Fraud and Elder Abuse of the Department of Justice, or their successor entities, shall adopt protocols, to the extent that these protocols are applicable to achieve the purpose of subdivision (b), similar to those adopted by the Department of Insurance concerning medical billing and provider fraud.

(b) An insurer, self-insured employer, third-party administrator, workers' compensation administrative law judge, audit unit, attorney, or other person that believes that a fraudulent claim has been made by any person or entity providing medical care, as described in Section 4600, shall report the apparent fraudulent claim in the manner prescribed by subdivision (a).

(c) An insurer, self-insured employer, third-party administrator, workers' compensation administrative law judge, audit unit, attorney, or other person that reports any apparent fraudulent claim under this section shall not be subject to any civil liability in a cause of action of any kind when the insurer, self-insured employer, third-party administrator, workers' compensation administrative law judge, audit unit, attorney, or other person acts in good faith, without malice, and reasonably believes that the action taken was warranted by the known facts, obtained by reasonable efforts.  This section does not abrogate or lessen the existing common law or statutory privileges and immunities of an insurer, self-insured employer, third-party administrator, workers' compensation administrative law judge, audit unit, attorney, or other person.