This bill creates new law by adding sections to three existing chapters of the RCW to require coverage for biomarker testing. It requires health carriers issuing plans under chapter 48.43 RCW and health plans offered to public employees under chapter 41.05 RCW to include coverage for biomarker testing for plans issued or renewed on or after January 1, 2026. It also requires the agency identified as "the authority" in chapter 74.09 RCW to provide coverage for biomarker testing beginning January 1, 2026. This is a procedural change imposing coverage obligations rather than a criminal or penalty change. Coverage must be provided when biomarker testing is supported by medical and scientific evidence, including at least one of: FDA approvals or labeled indications or FDA-indicated tests for an FDA-approved drug; CMS national or local coverage determinations; nationally recognized clinical practice guidelines; or consensus statements. The bill defines "biomarker," "biomarker testing," "consensus statements," and "nationally recognized clinical practice guidelines," requires carriers and the authority to limit disruptions in care (for example reducing the need for multiple biopsies or biospecimen samples), and directs the authority to seek federal financial participation under Title XIX (Medicaid) or other federal funding sources. Affected parties named in the bill include health carriers issuing plans under chapter 48.43 RCW, public employee health plans under chapter 41.05 RCW, and the unspecified "authority" administering chapter 74.09 RCW; the text also references FDA and CMS coverage determinations and the federal medical assistance program. The bill text provided does not give the specific RCW section numbers assigned to the new sections, does not identify or define the "authority," does not define "health carrier" within these extracts, and does not include details about coverage limits, cost-sharing, prior authorization, appeals, enforcement, or state funding appropriations. Sections 2 and 3 state that their defined terms have the same meanings as in section 1 of the act.

If enacted, starting January 1, 2026 health insurers selling plans under chapter 48.43 RCW, public employee health plans under chapter 41.05 RCW, and the unnamed state authority that administers chapter 74.09 RCW will be required to cover biomarker testing for diagnosis, treatment, management, or monitoring when that testing is supported by FDA approvals, CMS coverage determinations, nationally recognized clinical guidelines, or independent consensus statements. Insurers and the state authority must also arrange coverage to avoid unnecessary repeat biopsies or samples, and the state authority must try to obtain federal matching funds through Medicaid (Title XIX) or other federal sources. The most affected parties are health carriers, the public-employee plan administrators, the state authority, and patients who need biomarker tests. Carriers and the state program will likely face higher utilization and costs from added testing obligations and will need to adjust benefits and claims processes; the authority has the added responsibility of seeking federal funds to offset costs. Patients could see improved access to testing and fewer care interruptions. Key implementation details are missing, however: the bill text here does not name the authority, does not give specific RCW section numbers, and does not state how cost-sharing, prior authorization, enforcement, or funding will be handled.