California Code, Health and Safety Code - HSC § 1367.47

(a) The maximum amount a health care service plan may require an enrollee to pay at the point of sale for a covered prescription drug is the lesser of the following:

(b) A health care service plan shall not require a pharmacist or pharmacy to charge or collect from an enrollee a cost-sharing amount that exceeds the total retail price for the prescription drug.

(c) The payment rendered shall constitute the applicable cost sharing and shall apply to the deductible, if any, and also to the maximum out-of-pocket limit in the same manner as if the enrollee had purchased the prescription drug by paying the cost-sharing amount.