CMS star ratings hand Humana and Clover a sharp advantage for 2027
Federal Medicare Advantage star ratings for 2027 have redrawn the competitive map for major insurers just as open enrollment approaches. The new data put Humana and Clover Health among the clearest gainers, while Aetna, Alignment Healthcare, and parts of UnitedHealthcare faced softer results. Across the market, 71% of Medicare Advantage enrollees are now in plans that earned at least four stars, a level that remains central to bonus payments and marketing leverage in the program.
The threshold matters because Medicare Advantage star performance is not a cosmetic scorecard. It influences how plans are paid, how they are perceived by beneficiaries, and how aggressively they can compete during the annual enrollment period. Plans that clear four stars gain a meaningful financial and reputational edge, while lower scores can tighten margins and limit growth at exactly the moment consumers are comparing options.
Humana returns to the top tier after two weak years
Humana’s rebound stands out immediately. In 2025, 25% of its enrollees were in plans with four or more stars, and that share slipped to 20% in 2026. For 2027, it surged to 93%, nearly matching the company’s 94% level in 2024, according to the analyst review cited in the article.
This is not a marginal improvement. Humana’s four largest plans together cover about 68% of its Medicare Advantage book, and all four scored at least four stars. In practical terms, that gives the insurer a much broader platform for quality bonus payments and a cleaner story to tell beneficiaries shopping for coverage. After two lower-performing years, the swing suggests a more durable recovery rather than a single isolated gain.
The clinical analogy is straightforward: once a plan’s quality metrics move together, the entire performance profile changes. Beneficiaries may never see the measurement architecture behind the score, but they feel its effects through provider access, care management intensity, and the stability of supplemental benefits tied to the plan’s financial footing.
Clover Health’s jump triggers fresh attention on litigation risk
Clover Health posted one of the largest year-over-year moves in the set. Its share of members in plans with at least four stars climbed from just 3% in 2026 to 100% in 2027, after a volatile run in earlier years that included 0% in 2024 and 96% in 2025.
The company sits at the center of ongoing litigation that already forced score recalculations for 2026. In that case, a federal judge set aside about 20 metrics used in Clover’s scoring, and other insurers have watched closely as they consider similar challenges. The federal government has appealed the ruling, so the legal dispute remains unresolved.
Capstone analysts expect plans that suffered meaningful drops in 2027 to consider the same legal pathway if their performance can be challenged under the Clover precedent. The implication reaches beyond one insurer. If courts continue to narrow the measure set used in star ratings, the legal and actuarial assumptions behind the program could shift again before the 2028 cycle.
Aetna and Alignment absorb the steepest declines
The pressure moved in the opposite direction for Aetna. According to the analyst data, 69% of its members will be in plans with four or more stars in 2027, down from 81% in 2026. Three of its four largest contracts declined, together representing about 33% of its total Medicare Advantage book, and two of those plans fell below the four-star mark.
Aetna’s recent pattern shows how volatile this market can be. The insurer had already engineered a major turnaround in 2024 after only 21% of members were in four-star plans in the 2023 scores. One particularly damaging factor in that earlier period was a one-star drop in its National PPO Plan, which then represented more than half of total enrollment. The 2027 results suggest that quality gains can erode quickly when a few large contracts slip.
Alignment Healthcare also saw a steep decline. Only 25% of its members will be in plans with at least four stars for 2027, down from 100% in both 2025 and 2026. Its California HMO fell by half a star to 3.5, pulled down by two Health Outcomes Survey measures that carried triple weight in the 2027 calculation. Plans built around narrow score advantages can feel that kind of weighting change immediately.
CMS keeps trimming measures tied to administration rather than outcomes
The 2027 release fits a broader recalibration inside CMS. The agency has been working to align Medicare Advantage star ratings with the Universal Foundation, a quality framework built around just 10 measures drawn from HEDIS and CAHPS data. Eleven measures were deleted for the 2027 calculations and are being phased out by 2029 because CMS judged them too tied to administrative processes rather than direct member outcomes.
That shift changes the logic of competition. Plans that once depended on back-office precision, documentation workflows, or administrative efficiency may lose some of that advantage if those measures continue to fall away. In their place, outcome-linked metrics carry more weight, which favors organizations that can consistently deliver preventive care, patient experience, and measurable clinical follow-through.
UnitedHealthcare and Centene landed in the middle of the pack. UnitedHealthcare is projected to have about 67% of members in plans with at least four stars in 2027, down from 78% in 2026. Centene has remained weak for years, with just 1% of members in four-star plans in both 2024 and 2025, then 18% in 2026 before slipping to 9% in 2027. The analysts judged those results as largely neutral, but the trajectory is uneven enough to matter for future positioning.
The 2028 rulemaking cycle may decide who keeps winning
The next inflection point is already visible. CMS is expected to further reduce the number of measures in the CY28 Policy and Technical Changes Rule, a move that could penalize plans that have historically done well on administrative measures rather than direct patient outcomes. For insurers, this is not just a technical update; it is a structural rewrite of what quality means in Medicare Advantage.
As open enrollment begins on Oct. 15, these ratings will quickly become part of the consumer-facing story. Plans with stronger star results can market themselves more aggressively, while those that slipped will have to defend their value proposition in a crowded, highly regulated marketplace. The unresolved Clover litigation adds another layer of uncertainty, since future court decisions could alter how 2026 and later scores are interpreted.
The immediate reality is clear, even if the legal and regulatory picture is not. Medicare Advantage quality scoring is moving toward fewer measures, heavier emphasis on outcomes, and less tolerance for plans that rely on administrative finesse to stay near the top.