Cal. Ins. Code § 12693.15
"Supplemental coverage" means coverage purchased by the program from (a) a private health insurer holding a valid outstanding certificate of authority from the Insurance Commissioner, or (b) a health care service plan as defined under subdivision (f) of Section 1345 of the Health and Safety Code to bring the coverage available to purchasing credit members into at least 95 percent actuarial equivalence with the coverage provided to subscribers through the purchasing pool component of the program. The coverage shall provide for any necessary adjustment of the cost-sharing levels charged to purchasing credit members to be equivalent to those charged to subscribers through the purchasing pool component of the program. Subscriber costs and benefits for the purchasing credit members shall be at least 95 percent actuarially equivalent to subscriber costs and benefits in the purchasing pool component.
Ca. Ins. Code § 12693.15