California Code, Health and Safety Code - HSC § 132002

Except as provided in Section 132004, a person who manufactures a prescription drug shall not offer in the state a discount, repayment, product voucher, or other reduction in the individual's out-of-pocket expenses associated with his or her health insurance, health care service plan, or other health coverage, including, but not limited to, a copayment, coinsurance, or deductible, for a prescription drug if the active ingredients of the drug are contained in products regulated by the federal Food and Drug Administration, are available without prescription at a lower cost, and are not otherwise contraindicated for treatment of the condition for which the prescription drug is approved.