This bill amends existing law (RCW 48.43.600 and related 2025 c 227 s 7) to set time limits and procedures for health carriers requesting refunds from health care providers for payments already made to satisfy a claim. Section 1 takes effect January 1, 2027. Under the amendment, except for fraud or specific exceptions, a carrier must make a written refund request within six months of the payment date; for coordination of benefits the written request must be made within nine months and must include the name and mailing address of the entity with primary payment responsibility. A carrier may not require a contested refund to be paid any sooner than six months after the carrier’s receipt of the refund request. A provider has 30 days after receiving a refund request to contest it in writing; if the provider does not do so the request is deemed accepted and the refund must be paid. A carrier may request a refund at any time when a third party, including a government entity, is found legally responsible for the claim and the carrier is unable to recover from that third party because the third party has already paid or will pay the provider. The statute defines “refund,” says the statute prevails over conflicting contracts, allows providers to voluntarily refund at any time, and excludes dental-only carriers, Medicare Part A/B services (Title XVIII), and Medicare supplemental plans under chapter 48.66 RCW. This is a procedural change that amends existing statutory refund rules (time limits, notice and contest procedures, and coordination-of-benefits requirements). The text includes a parenthetical reference to mental health and substance use disorder services as defined in RCW 48.43.766. The extracted material does not include the prior statutory text for direct comparison and contains no separate appropriation, enforcement details, or broader implementation guidance.

If enacted, the law will limit when health insurers can try to claw back payments: in most cases insurers must put refund requests in writing within six months of payment (nine months when coordination of benefits is involved and they must identify the primary payer), and they must explain why the money is owed. Providers must contest those requests in writing within 30 days or the request is automatically accepted and the provider must repay; insurers also cannot force a contested refund to be paid any sooner than six months after they make the request. Insurers retain the ability to seek refunds at any time when a third party (including a government or tortfeasor) is found responsible and the carrier cannot otherwise recover, and the statute overrides any contract terms that would conflict with these rules. The change would not apply to dental-only carriers or Medicare and most Medicare supplement arrangements, and it becomes effective January 1, 2027. The people most affected are health insurers and health care providers: insurers will need to move faster and be more precise in written requests or lose the chance to recover overpayments, while providers face a real cash‑flow and compliance risk if they miss the 30‑day contest window. Insurers also lose the ability to demand accelerated repayment of contested amounts. The text does not include enforcement procedures, how fraud exceptions are handled in practice, or the previous statutory text for full comparison, so some operational details and how disputes will be resolved remain unclear.