Cal. WIC § 4659.23

In order to assess overlapping or duplicate health coverage, every health insurer, self-insured plan, group health plan, as defined in Section 607(1) of the federal Employee Retirement Income Security Act of 1974 (29 U.S.C. Sec. 1001 et seq.), service benefit plan, managed care organization, including a health care service plan as defined in subdivision (f) of Section 1345 of the Health and Safety Code, licensed pursuant to the Knox-Keene Health Care Service Plan Act of 1975 (Chapter 2.2 (commencing with Section 1340) of Division 2 of the Health and Safety Code), pharmacy benefit manager, or other party that is, by statute, contract, or agreement, legally responsible for payment of a claim for a health care item or service shall maintain a centralized file of the subscribers’, policyholders’, or enrollees’ names, mailing addresses, and social security numbers or dates of birth, and where available, for all other covered persons, the names and social security numbers or dates of birth. This information shall be made available to the department or a regional center upon reasonable request. Notwithstanding Section 20230 of the Government Code, the Board of Administration of the Public Employees’ Retirement System and affiliated systems or contract agencies shall permit data matches with the state department to identify consumers with third-party health coverage or insurance.