Assembly Member Bonta's proposal to eliminate cost-sharing requirements for Californians under age 21 marks a substantial shift in health care coverage requirements for insurers and health plans operating in the state. The legislation would prohibit deductibles, copayments, coinsurance, and other cost-sharing mechanisms for medical services provided to enrollees and insured individuals under 21 years of age, starting January 1, 2026.

The bill creates specific provisions for high-deductible health plans (HDHPs) that qualify for use with health savings accounts under federal law. These plans would maintain their deductible requirements but could not impose cost-sharing for preventive care services for those under 21. Once an HDHP's annual deductible is met, the plan could not require additional cost-sharing for any services provided to enrollees or insured individuals under 21 for the remainder of the plan year.

The measure applies to both health care service plans regulated by the Department of Managed Health Care and disability insurance policies overseen by the Department of Insurance. The bill includes provisions making willful violations by health plans a criminal offense, though local agencies and school districts would not require state reimbursement for any associated enforcement costs.