Revised Code of Washington-Title 48-Chapter 48.43. Insurance Reform
Prohibition against retrospective denial of health plan coverage — Rules.
(1) A health carrier that offers a health plan shall not retrospectively deny coverage or retrospectively modify to a service less intensive than that included in an approved request for emergency and nonemergency care that had prior authorization, including for medical necessity, under the plan's written policies at the time the care was rendered, unless:
(a) The approved prior authorization was based upon a material misrepresentation by the provider, facility, or covered person; or
(b) The underlying health plan coverage is lawfully rescinded, canceled, or terminated retrospectively through the date of service.
(2) Retrospective denials of services with an approved prior authorization or retrospective modification of an approved prior authorization to less intensive services due to a change in the carrier's determination of medical necessity are prohibited, shall not be considered adverse benefit determinations, and will not be required to follow the standard appeals processes in RCW 48.43.530 or any carrier policies related to their own grievance and appeals process. If an enrollee, or the provider requesting the authorization demonstrates the authorization was valid per the plan's written policies, then the carrier will deem the authorization approved and payable. Interest will be assessed on the associated claim submitted by the provider at the rate of one percent per month, retroactive to the date of submission. An enrollee, or provider on behalf of the enrollee, may seek review by an independent review organization under RCW 48.43.535 without the need to engage in, exhaust, or wait for any timelines related to the carrier's grievance process.
(3) This section does not prevent carriers from reimbursing only for services billed and rendered.
(4) The commissioner shall adopt, in rule, standards for this section after considering relevant standards adopted by national managed care accreditation organizations and state agencies that purchase managed health care services.
This section was amended in 2026 by the enactment of Senate Bill 5395 (2026).