California Code, Health and Safety Code - HSC § 1374.195

(a) With respect to a contract between a health care service plan or specialized health care service plan and a dentist to provide covered dental services to enrollees of the plan, the contract shall not require a dentist to accept an amount set by the plan as payment for dental care services provided to an enrollee that are not covered services under the enrollee's plan contract. This subdivision shall only apply to provider contracts issued, amended, or renewed on or after January 1, 2011.

(b) A provider shall not charge more for dental services that are not covered services under a plan contract than his or her usual and customary rate for those services. The department shall not be required to enforce this subdivision.

(c) The evidence of coverage and disclosure form, or combined evidence of coverage and disclosure form, for every health care service plan contract covering dental services, or specialized health care service plan contract covering dental services, that is issued, amended, or renewed on or after July 1, 2011, shall include the following statement:

IMPORTANT: If you opt to receive dental services that are not covered services under this plan, a participating dental provider may charge you his or her usual and customary rate for those services. Prior to providing a patient with dental services that are not a covered benefit, the dentist should provide to the patient a treatment plan that includes each anticipated service to be provided and the estimated cost of each service. If you would like more information about dental coverage options, you may call member services at [insert appropriate telephone number] or your insurance broker. To fully understand your coverage, you may wish to carefully review this evidence of coverage document.

(d) For purposes of this section, “covered services” or “covered dental services” means dental care services for which the plan is obligated to pay pursuant to an enrollee's plan contract, or for which the plan would be obligated to pay pursuant to an enrollee's plan contract but for the application of contractual limitations such as deductibles, copayments, coinsurance, waiting periods, annual or lifetime maximums, frequency limitations, or alternative benefit payments.