Cal. Gov. Code § 22764
"Carrier" means a private insurance company holding a valid outstanding certificate of authority from the Insurance Commissioner, a medical society or other medical group, a nonprofit membership corporation lawfully operating under Section 10270.5 of the Insurance Code, a health care service plan as defined under subdivision (f) of Section 1345 of the Health and Safety Code, or a health maintenance organization approved under Title XIII of the federal Public Health Services Act (42 U.S.C. Sec. 201 et seq.) that is lawfully engaged in providing, arranging, paying for, or reimbursing the cost of personal health services under insurance policies or contracts, medical and hospital service agreements, membership contracts, or the like, in consideration of premiums or other periodic charges payable to it.
Ca. Gov. Code § 22764