Cal. Lab. Code § 4616.5

(a) For purposes of this article, “employer” means a self-insured employer, joint powers authority, or the state.
(b) For purposes of this article, “entity that provides physician network services” means a medical network licensed by the Department of Insurance or Department of Managed Health Care, or a third-party claims adjusting organization licensed by the Department of Insurance or certified by the Office of Self-Insurance Plans, or a legal entity that offers medical management or physician network services within California.
(c) For purposes of this article, “entity that provides ancillary services” means an entity that provides medical services or goods, as authorized by Section 4600, by a nonphysician, including, but not limited to, interpreter services, physical therapy, and pharmaceutical services.