CMS Star Ratings Recalculation After Clover: Asymmetric Design and 2027 MA Bid Methodology Risk

U.S. District Judge Lisa Godbey Wood ruled May 27, 2026 that CMS unlawfully included 20 measures in its 2026 Medicare Advantage star ratings calculation and ordered a recalculation that upgraded Clover Health's primary PPO contract from 3.5 to 4.5 stars, recovering an estimated $120 million in missed bonus payments (Clover Health 8-K, June 2026). CMS applied the correction asymmetrically: only upward rating changes took effect, leaving 2026 ratings legally deficient as the 2027 bid cycle opens.

The Step-Function Economics That Make Litigation Rational

The mechanics that made Clover's lawsuit worth fighting start with how CMS distributes approximately $12.8 billion in annual Medicare Advantage quality bonus payments (KFF, 2023). The structure is not a gradient. Plans rated 3.5 stars or above receive a quality bonus payment equal to 3.5 percentage points applied to their applicable county benchmark; plans at 4.0 stars or above receive a 5.0-percentage-point bonus. At a $1,200 county benchmark, that 1.5-point differential adds $18 per member per month of ceiling revenue before a single benefit dollar is committed. For a plan with 50,000 members, the annual swing is $10.8 million from the QBP alone.

The rebate structure at the same threshold compounds the effect. Plans below 4.0 stars return 50% of the benchmark-to-bid spread to members as supplemental benefits or premium reductions; plans at 4.0 return 65%; plans at 4.5 or above return 70% (CMS Rate Announcement, April 2026). A plan that crosses from 3.5 to 4.0 stars picks up both the higher QBP floor and the higher rebate percentage simultaneously. On a $150 benchmark-to-bid spread, the rebate improvement alone moves from $75 to $97.50 per member per month, adding $1.35 million annually to the benefit budget of that same 50,000-member plan.

TD Cowen analysts estimated that if the Clover rationale had been applied uniformly across the industry, UnitedHealthcare alone would have gained approximately $500 million in additional quality bonus payments (Healthcare Dive, June 2026). That figure, derived from UHC's average score moving from 4.11 to 4.27 stars under the revised measure set, makes the concentration of program value at the 4-star step function explicit. Any plan sitting at 3.5 stars with a viable legal challenge faces an expected-value calculation that comfortably justifies federal litigation.

Medicare Advantage Quality Bonus Payment and Rebate Structure by Star Tier
Star Rating	QBP Benchmark Addition	Rebate Return Rate	Illustrative Annual Swing per 50K Members
Below 3.5 stars	None	50%	Baseline
3.5 stars	+3.5 ppts of county benchmark	50%	+$25.2M vs. sub-3.5
4.0 stars	+5.0 ppts of county benchmark	65%	+$10.8M QBP + $13.5M rebate vs. 3.5 stars
4.5 stars	+5.0 ppts of county benchmark	70%	+$5.4M additional rebate vs. 4.0 stars

Sources: CMS Rate Announcement (April 2026); CMS Social Security Act Part C bid framework. Illustrative swing uses $1,200 county benchmark, $150 bid-to-benchmark spread, 50,000 members; actual results vary by contract geography and member count.

Two Legal Theories, One Structural Vulnerability

The court's analysis separated the 20 challenged measures into two categories, each with a distinct legal rationale and different implications for which additional measures might be at risk. The first group of 10 included medication adherence measures and call center data that CMS collected outside its statutory authority over MA quality improvement programs. Judge Wood found the agency exceeded that authority by relying on data sources not specified in the governing statute (Clover Insurance v. HHS, S.D. Ga., May 2026).

The second rationale carries broader exposure. CMS has routinely updated star rating measure specifications through technical notes and sub-regulatory guidance, often adjusting dozens of measures annually without triggering formal notice-and-comment rulemaking. Because changes to measure specifications directly affect payment levels, the court found they constituted substantive legal standards requiring public rulemaking under the Administrative Procedure Act. That logic, if it survives appeal, reaches well beyond the 10 measures challenged by Clover. The pool of star rating measures updated through sub-regulatory channels over the past several years is far larger than 10.

CareFirst BlueCross BlueShield secured a two-week pause in its own parallel lawsuit in June 2026, pointing to the Clover ruling as grounds for CMS to reconsider its methodology more broadly (Becker's Payer Issues, June 2026). CareFirst's contract covers approximately 30,000 Medicare Advantage beneficiaries in Maryland, and the plan claims a CMS miscalculation dropped its rating to 3.5 stars rather than 4.0, costing more than $32 million in quality bonus payments for 2027 (Georgetown Health Care Litigation Tracker, June 2026). The pause rather than a dismissal preserves the precedent channel for additional challenges before the 2027 ratings cycle concludes.

Three Consecutive Years: Pattern Replaces Anomaly

Tracking the litigation history across three consecutive plan years clarifies what changed in June 2026. CMS recalculated its 2024 star ratings after successful lawsuits by SCAN Health Plan, Zing Health, and Elevance Health, eventually adding approximately $1 billion in bonus payments across the industry (RISE Health, 2025). A second wave of litigation-driven adjustments followed for 2025 plan year ratings. The Clover recalculation for 2026 marks the third consecutive year in which published star ratings were revised after successful litigation.

The practical implication for bid actuaries is not about litigation strategy. It is about what the star rating itself represents as a modeling input. In a stable rulemaking environment, the published star rating functions as a near-certain revenue assumption: performance risk, which is the probability that the plan achieves or maintains its target rating on remaining valid measures, is the primary variable, and the methodology is treated as fixed. Three consecutive years of successful litigation means the methodology is no longer fixed. It carries its own distribution of outcomes, distinct from the plan's clinical performance. A plan currently sitting at 3.5 stars building 2027 bids faces two independent sources of rating uncertainty: performance risk on the measures that remain, and methodology risk that those measures or additional ones may be invalidated or revised before 2027 ratings are finalized.

The asymmetric design of CMS's current recalculation approach introduces a directional skew to that methodology risk. If a subsequent court ruling or voluntary CMS action removes measures that the plan performed well on, the plan's star rating may fall, and the asymmetric recalculation approach used in 2026 provides no upside protection in that direction. Plans whose current rating rests disproportionately on measures with legal vulnerability face a one-sided methodology risk: they can gain from an upward recalculation but cannot recover from a downward one under the current recalculation design.

Building the 2027 Bid Scenario Matrix

A defensible 2027 bid actuarial memorandum for any plan within half a star of the 4.0-star threshold needs to address three scenarios explicitly rather than treating the current rating as a fixed input.

Scenario one: methodology stabilizes as-is. CMS retains the remaining measures without further litigation or voluntary revision before 2027 ratings are published. The plan's revenue assumption rests entirely on performance projections for the surviving measure set. For plans already above 4.0 stars by a comfortable margin, this is the low-risk scenario. For plans at 3.5 stars, it is also the ceiling: no methodology change improves their position, and the only path to 4.0 stars runs through clinical performance alone.

Scenario two: CMS proactively removes additional vulnerable measures. The agency reviews remaining star rating measures for the same two legal vulnerabilities identified in Clover and suspends or withdraws measures before 2027 ratings are finalized. This scenario reshuffles scores in both directions. A plan that performed poorly on a subsequently removed measure could see its rating rise, potentially crossing the 4.0 threshold and unlocking the rebate tier and QBP improvement simultaneously. A plan that performed well on the same removed measures faces a rating reduction under the asymmetric recalculation design.

Scenario three: additional litigation succeeds. CareFirst or a new plaintiff wins a comparable ruling, triggering another industry-wide recalculation before 2027 ratings are published. The dollar impact of scenario three varies by plan position and by which measures the new ruling covers. Plans whose legal exposure differs from Clover's may face a completely different measure removal set, making the revenue swing under scenario three genuinely non-correlatable with the scenario two outcome from a bid modeling perspective.

The bid documentation implication is that sensitivity analysis limited to clinical performance does not capture the full revenue distribution a plan faces entering the 2027 cycle. Each scenario should carry an explicit probability weight, a revenue PMPM outcome by star tier outcome, and a description of which contract characteristics drive the plan's exposure in that scenario. That work is the same analysis that would support a resubmission decision if the recalculation does shift the plan's rating after bids close.

The Supplemental Benefit Cascade

The connection from star ratings litigation to supplemental benefit budgeting runs through rebate mechanics. Plans near the 4.0-star threshold compete aggressively on supplemental benefits, offering dental, vision, hearing, and over-the-counter allowances funded from the rebate generated when the plan bid falls below the county benchmark. That rebate is a function of both the benchmark ceiling, which rises with a higher QBP tier, and the rebate percentage, which steps from 50% to 65% at the 4.0-star boundary. A plan that qualifies for 65% rather than 50% rebate return on a $150 bid margin recovers an additional $22.50 per member per month for supplemental benefits, roughly $13.5 million annually at 50,000 members.

Methodology risk introduces a two-sided problem for benefit-design actuaries. Plans that might move to 4.0 stars under a favorable recalculation scenario face the temptation to pre-price supplemental benefits assuming the higher rebate tier, locking in commitments funded by revenue they may not receive if the scenario does not materialize. Plans currently above 4.0 stars face the converse: if scenario two removes measures they performed well on and their rating drops, the rebate compression hits the benefit budget in a plan year where contracts are already committed to members. Benefit-design actuaries who have not incorporated the scenario matrix into supplemental benefit funding assumptions are effectively betting on scenario one while carrying scenario two and three exposure on the balance sheet.

The enrollment consequence compounds the financial one. Plans that offer richer supplemental benefits than their competitors attract a member mix with specific chronic condition patterns and care-seeking behavior. A mid-year benefit reduction driven by an unexpected star rating decline concentrates adverse selection on the plan that cannot sustain the benefit package it competed on, while competitors who priced more conservatively retain members at more favorable risk profiles.

What the Actuarial Memorandum Needs to Carry

Patterns across three consecutive litigation cycles suggest the star ratings program has entered a period of structural instability that is more likely to persist than to resolve quickly. The notice-and-comment rationale from the Clover ruling applies to a large share of CMS's historical practice of updating measure specifications sub-regulatorily. If CMS begins rulemaking to legitimize that practice prospectively, the rulemaking cycle itself introduces a two-to-three-year window of uncertainty before new measure specifications carry uncontested legal standing. If CMS instead loses additional lawsuits and recalculates ratings again for 2027, the asymmetric design of the correction means every plan that sees its rating fall under the adjustment bears the full loss, while plans that benefit retain their improvement.

For the 2027 bid submission, the practical task is to quantify the revenue swing associated with each scenario, assign probability weights the actuary can defend, and document the assumptions in the memorandum at a level of specificity that would survive a CMS bid review or an audit inquiry about the revenue assumptions. A memorandum that treats the 2026 star rating as a fixed input, and performs sensitivity analysis only on clinical performance risk, does not reflect the known legal uncertainty that has now materialized in three consecutive plan years. Actuaries who document that uncertainty explicitly, with scenario weighting, will be in a materially better position if CMS does recalculate again, whether because a court orders it or the agency acts voluntarily, and resubmission rights need to be exercised quickly.

CareFirst's decision to pause rather than drop its lawsuit preserves the litigation channel through at least the early 2027 ratings preparation period. Whether additional plans file between now and the September 2026 preliminary 2027 star ratings release will depend on how many plans ran internal analyses after the Clover ruling and found comparable measure-level exposure. That analysis is not speculative. It is the same measurement work the plan does to forecast its star rating each year, re-run against the Clover decision's two legal tests for each measure currently in the calculation.