CA AB1859

Requires health care service plans and health insurers to approve medically necessary mental health and substance use disorder treatment for individuals detained under the Lanterman-Petris-Short Act (involuntary psychiatric holds), effective for contracts issued, amended, or renewed on or after July 1, 2023.

Mandates health plans and insurers process referrals for voluntary follow-up mental health appointments as appointment requests and arrange in-network or out-of-network coverage to meet geographic and timely access standards if in-network options are unavailable.

Prohibits noncontracting providers from billing patients more than the in-network cost-sharing amount for covered mental health or substance use disorder treatment; requires plans and insurers to inform patients and providers of the applicable in-network cost-sharing amount.

Exempts Medi-Cal managed care plans and Medi-Cal insurance policies from these requirements.

Declares no state reimbursement is required for local agencies or school districts under Article XIII B of the California Constitution because any costs relate to criminal law changes.