“Participating health plan” means any of the following plans that is lawfully engaged in providing, arranging, paying for, or reimbursing the cost of personal health care services under insurance policies or contracts, medical and hospital service arrangements, or membership contracts, in consideration of premiums or other periodic charges payable to it, and that contracts with the board to provide coverage to program subscribers:
(a) A private health insurer holding a valid outstanding certificate of authority from the commissioner.
(b) A health care service plan as defined under subdivision (f) of Section 1345 of the Health and Safety Code.
(c) A county organized health system.
(d) A local initiative.