Medicare Star Ratings After Clover Insurance v. HHS: Why Medication Measures Still Matter

Why medication adherence and optimization remain essential for health outcomes, cost savings, and quality performance.

The recent court ruling in Clover Insurance Co. v. HHS has sparked widespread discussion across the Medicare Advantage industry. Much of the conversation has centered on Medicare Star Ratings and which quality measures may ultimately remain in the program.

But for health plans, the more important question is: Should medication adherence and optimization remain strategic priorities, even if quality measures change?

The answer is unequivocally yes.

Medication optimization has always delivered value beyond Star Ratings. It remains one of the most effective ways to improve outcomes for members with chronic disease while reducing avoidable healthcare utilization and total cost of care.

The stakes extend far beyond quality scores. Medication-related problems are estimated to contribute to hundreds of billions of dollars in avoidable healthcare costs annually, driven by preventable hospitalizations, emergency visits, and complications from non-optimized medication use. As we'll explore below, those results remain just as relevant regardless of how quality measures evolve.

Whether CMS changes how quality is measured does not change the underlying clinical and economic value of helping members receive the right medications and take them consistently. For health plans, medication optimization is fundamentally a clinical strategy and not just a quality reporting strategy.

What did the Clover v. HHS ruling actually decide?

The Clover decision invalidated 20 Medicare Advantage quality measures—not because the court found the measures clinically unimportant, but because it found legal flaws in how the Centers for Medicare & Medicaid Services (CMS) implemented them. Some measures relied on data sources outside the three congressionally authorized quality improvement programs (HEDIS, CAHPS, and HOS), while others were implemented through Technical Specifications and other guidance without the required notice-and-comment rulemaking. The court concluded that these actions exceeded CMS's statutory authority.

Importantly, the ruling did not conclude that medication-use quality measures lack clinical value.

Clinical outcomes still depend on medications

Regardless of how quality measures evolve, medication adherence remains one of the strongest predictors of outcomes for members with chronic disease. CMS's proposed MY2027 Star Ratings would return these measures to triple weighting, reflecting their importance in improving outcomes for chronic conditions.

Measured by Proportion of Days Covered (PDC), adherence measures consistently rank among the lowest-performing Medicare Star Rating measures. Their persistent underperformance underscores how difficult it is for patients to start and stay on therapy, and why improving adherence remains one of the most impactful opportunities to reduce avoidable complications, hospitalizations, and total cost of care.

The clinical impact of adherence is well established:

• Diabetes: Improved medication adherence was associated with 13% lower odds of hospitalization or emergency department visits, with the potential to prevent 699,000 ED visits, 341,000 hospitalizations, and nearly $5 billion in annual healthcare spending, according to a national analysis published in Health Affairs.
• Hypertension: A study of more than three million adults found that patients with poor adherence to antihypertensive medications were more than four times as likely to experience preventable hypertension-related hospitalizations than patients with high adherence, resulting in substantially higher healthcare costs.
• Cholesterol: Patients with high statin adherence (PDC ≥80%) incurred 14% lower total healthcare costs, driven by lower medical utilization despite higher pharmacy spending, according to research published in the Journal of Managed Care & Specialty Pharmacy.

Members with unresolved medication problems, like unmanaged polypharmacy, also experience higher rates of hospitalization, adverse events, and avoidable healthcare spending. For example, a nationwide cohort study of more than three million older adults found that polypharmacy was associated with significantly higher rates of hospitalization and all-cause mortality, with risk increasing as the number of medications increased. Likewise, the National Institute on Aging and the American Geriatrics Society's Beers Criteria identify inappropriate polypharmacy—particularly involving CNS-active and anticholinergic medications—as a major patient safety concern because of its association with falls, cognitive impairment, and functional decline.

Those clinical risks and their associated costs demonstrate why medication measures matter beyond any individual quality program. Whether medication quality measures appear in Star Ratings, HEDIS, Display Pages, or another quality program, the objective is still to help patients receive the right medications, use them appropriately, and avoid preventable complications.

What Arine sees across millions of members

Arine's Medication AI platform analyzes medication use across millions of members to identify gaps in care, adherence barriers, and opportunities for optimization. Across an analysis of six health plans, members adherent to diabetes, RASA, or statin medications had measurable, consistent advantages over nonadherent members with similar clinical profiles:

• More than 10% fewer inpatient admissions among adherent members across all three drug classes (diabetes, RASA, statin).
• More than $800 in medical cost savings per member per year for diabetes and RASA medication adherence.
• Nearly $400 in medical cost savings per member per year for statin adherence.

We also find evidence that reducing polypharmacy, including concurrent opioid and benzodiazepine use, can reduce total cost of care by 10-15%. For higher-risk members specifically, MTM interventions reduce total cost of care by 7%. Arine's findings are consistent with the above findings from the literature.

Regardless of whether a metric appears in Medicare Star Ratings or not the underlying clinical driver is the same:

Patients who take the right medication, correctly and consistently, have fewer preventable hospitalizations.

The risk of misreading this ruling as permission to pull back

The most consequential error a Medicare Advantage plan could make right now is treating the Clover ruling as a reason to deprioritize medication management programs. The members who were nonadherent, on inappropriate medication combinations, or missing statin therapy before the ruling are in the same clinical situation today. The measure's status in a CMS formula doesn’t change their risk profile.

The ruling doesn't change the fact that medication issues still lead to hospitalizations, ED visits, and higher healthcare costs. If plans reduce their focus on medication optimization, they'll still bear those costs—even if they're no longer reflected in Star Ratings.

What plans should do now

Rather than viewing the Clover ruling as a reason to scale back medication management efforts, health plans should see it as an opportunity to reinforce the strategies that consistently improve clinical and financial outcomes. The evidence hasn't changed. Optimizing medication use remains one of the most effective ways to prevent avoidable complications, improve member health, and reduce total cost of care.

Successful medication strategies focus on these priorities:

• Identify medication-related risk before it becomes a hospitalization — flagging non-adherence, drug interactions, and therapy gaps early.
• Address the root causes of nonadherence — affordability, complex medication regimens, health literacy, care transitions, and prescriber gaps.
• Target Comprehensive Medication Reviews (CMRs) to the members most likely to benefit, rather than spreading outreach evenly.
• Close polypharmacy, statin, and adherence gaps proactively, using data to prioritize outreach instead of waiting for a measurement cycle.
• Equip pharmacists and care managers with AI-driven insights, so they spend more time on high-value clinical interventions and less time searching for those who need attention.

The health plans that continue investing in medication optimization will be better positioned to improve member outcomes, reduce avoidable medical costs, and succeed regardless of how quality programs evolve.

The Clover ruling may influence future CMS rulemaking, congressional action, or even the structure of the Medicare Star Ratings program. But it should not change the industry's commitment to medication optimization.

Because regardless of how CMS measures quality, better medication use still leads to better health.

Key questions about Clover v. HHS and Medicare Star Ratings

Does the Clover ruling diminish the importance of medication adherence?

No. The ruling addressed CMS's authority to use certain data sources and not whether medication adherence improves clinical outcomes. The clinical evidence supporting medication adherence remains strong.

Should health plans continue investing in medication optimization?

Yes. Medication optimization reduces preventable hospitalizations, emergency department visits, and total medical costs while improving outcomes, especially for members with chronic conditions.

How does AI improve medication management?

Arine’s Medication AI transforms fragmented clinical and medication data into actionable insights for health plans and care teams. By learning from millions of medication decisions, interventions, and outcomes, it identifies the members most likely to benefit and prioritizes the actions with the greatest potential impact. This enables pharmacists and clinicians to focus on improving outcomes, closing care gaps, and reducing avoidable costs at scale.

Is medication optimization only important for Medicare Advantage?

No. Medication-related problems drive unnecessary costs across Medicare, Medicaid, and Commercial populations. Optimizing medication use improves outcomes across all lines of business.