Cal. Health & Saf. Code § 1371.3
On and after January 1, 1994, every group health care service plan that provides hospital, medical, or surgical expense benefits for plan members and their dependents shall authorize and permit assignment of the enrollee's or subscriber's right to any reimbursement for health care services covered under the plan contract to the State Department of Health Services when health care services are provided to a Medi-Cal beneficiary. This section, however, shall not apply to a Medi-Cal beneficiary for health care services provided pursuant to a contract with the State Department of Health Services under Chapter 7 (commencing with Section 14000) or Chapter 8 (commencing with Section 14200) of Part 3 of Division 9 of the Welfare and Institutions Code.
Ca. Health and Saf. Code § 1371.3