WA SB5477

Updates Washington's mental health parity law to require health carriers to cover mental health and substance use disorder services at parity with medical and surgical services, including equal copayments, coinsurance, deductibles, and treatment limitations

Requires utilization review and clinical review criteria to be consistent with generally accepted standards of mental health and substance use disorder care, using evidence-based sources such as peer-reviewed studies and nonprofit professional association guidelines

Prohibits health carriers from requiring prior authorization for inpatient or residential mental health or substance use disorder treatment in licensed behavioral health agencies, and mandates minimum 2-3 day coverage before utilization review can begin

Establishes civil penalties of up to $5,000 per violation ($10,000 for willful violations) for carriers that violate parity requirements, and requires carriers to provide nonquantitative treatment limitation parity compliance analyses free of charge upon request

Takes effect January 1, 2026, and repeals existing mental health service coverage statutes (RCW 48.20.580, 48.21.241, 48.41.220, 48.44.341, and 48.46.291) to consolidate requirements under the new provisions