California Code, Health and Safety Code - HSC § 1374.19

(a) This section shall only apply to a health care service plan covering dental services or a specialized health care service plan contract covering dental service pursuant to this chapter.

(b) For purposes of this section, the following terms have the following meanings:

(c) A health care service plan covering dental services or a specialized health care service plan issuing a specialized health care service plan contract covering dental services shall declare its coordination of benefits policy prominently in its evidence of coverage or contract with both enrollee and subscriber.

(d) When a primary dental benefit plan is coordinating its benefits with one or more secondary dental benefits plans, it shall pay the maximum amount required by its contract with the enrollee or subscriber.

(e) A health care service plan covering dental services or a specialized health care service plan contract covering dental services, when acting as a secondary dental benefit plan, shall pay the lesser of either the amount that it would have paid in the absence of any other dental benefit coverage, or the enrollee's total out-of-pocket cost payable under the primary dental benefit plan for benefits covered under the secondary plan.

(f) Nothing in this section is intended to conflict with or modify the way in which a health care service plan covering dental services or a specialized health care service plan covering dental services determines which dental benefit plan is primary and which is secondary in coordinating benefits with another plan or insurer pursuant to existing state law or regulation.