This bill adds a new section to chapter 48.43 RCW that establishes a minimum medical loss ratio (MLR) of at least 90 percent for health plans. The MLR requirement applies to health plans issued or renewed on or after January 1, 2027, and the bill allows the commissioner to adopt rules necessary to implement the section. The term "medical loss ratio" is defined by reference to the federal regulation 45 C.F.R. Sec. 158.221 (2025) as of January 1, 2026. Legally, this is a new statutory requirement setting a substantive threshold for the portion of premium dollars that must be spent on medical care and health care quality (a new law), and it includes a procedural authorization for rulemaking by the unspecified commissioner. The text provided does not specify which commissioner or define "health plans," and it does not include any compliance, enforcement, reporting, calculation detail, exceptions, or penalty provisions beyond the cross-reference to the federal MLR definition. Bill identifier and legislative details in the extract: S-3712.1 / Senate Bill 5953, sponsored by Senators Slatter, Robinson, Hasegawa, and Nobles, referred to the Senate Committee on Health & Long-Term Care, prefiled December 29, 2025, and read for the first time January 12, 2026.

If enacted, starting January 1, 2027 any health plan issued or renewed in Washington would have to meet a minimum medical loss ratio of 90 percent as measured by the federal rule cited, which effectively forces insurers to direct at least 90 cents of every premium dollar toward medical care and quality improvement rather than administrative costs or profits. Insurers offering plans in the state are the most directly affected: they will likely need to change pricing, benefits, reserve practices, or cost structures to meet that threshold, and may face increased pressure on margins or fewer plan options if they cannot meet the ratio. The commissioner is given authority to adopt rules to implement the change, so regulatory guidance and compliance requirements will follow, but the bill text provided does not say which commissioner, which specific types of plans are covered, or how compliance, enforcement, or any consumer remedies would work, leaving those important details uncertain.