Frost Health LawAlabama Attorney • Pharmacist • Healthcare Executive

Medicare • Pharmacy Quality • Medication Adherence • Administrative Law • Pharmacy Litigation

CVS Challenges Medicare Star Ratings, Including Medication Adherence Measures

CVS Health and its insurer subsidiaries sued HHS and CMS October 26 over the 2027 Medicare Star Ratings. Their complaint challenges the adoption of 28 criteria and the statutory basis for data used in 12. It also questions whether claims-based medication adherence reflects clinical care accurately. CVS projects more than $2 billion in affected 2028 payments. These are litigating positions and estimates. Pharmacy leaders should examine the dispute’s implications for data quality, transparent methods, and review procedures.

By Toby C. “Chad” Frost • October 28, 2026
2 min read

A challenge to plan ratings and payment methods

CVS Health and its insurer subsidiaries filed this action October 26, 2026, in the Southern District of Georgia, No. 2:26-cv-00115. They seek recalculation of their 2027 Medicare Star Ratings. CVS alleges that 28 challenged criteria lacked required notice-and-comment adoption and that 12 also relied on data outside CMS’s statutory authority. It projects more than $2 billion in affected 2028 quality bonuses and rebate retention. These assertions and estimates remain the plaintiffs’ positions.1

CMS confirms that the 2027 ratings appear in Medicare Plan Finder and affect 2028 Medicare Advantage quality bonus payments. Its October 8 fact sheet says methodology changes went through prior notice-and-comment rulemaking. That general explanation is distinct from a response to the individual claims in this lawsuit. No later merits ruling was verified as of October 28, 2026.23

The pharmacy connection is in the underlying data

Paragraph 64 argues that adherence calculations may miss cash purchases, Veterans Affairs fills, or transactions processed through other coverage. CVS also argues that dispensing records cannot establish consumption or reliably distinguish missed treatment from appropriate clinical changes. Paragraph 65 challenges derivative improvement calculations and their influence on the overall result.1

CMS’s published weights assign a weight of three to the diabetes, hypertension, and statin adherence indicators, and five to Drug Plan Quality Improvement. Those specifications establish how the agency weights these components; CVS’s allegations do not establish that the resulting scores are unlawful or clinically invalid.14

Ask the same practical questions about every payment metric

Chad’s analysis: The useful operational questions concern data completeness, attribution, clinical exceptions, transparency, and correction procedures. Before accepting a score that affects payment, identify its inputs and exclusions, test how outside fills and treatment changes are handled, and preserve evidence of errors. Pharmacy owners can apply that review framework to their own agreements. Any comparison with PBM performance terms should identify the actual contract language and governing law rather than assume that a Medicare plan dispute resolves a separate contract question.

Source notes

  1. Complaint ¶¶ 1–10, 49–50, 64–71, 73–82 & Prayer for Relief at 34–35, CVS Health Corp. v. Dep’t of Health & Hum. Servs., No. 2:26-cv-00115-LGW-BWC (S.D. Ga. Oct. 26, 2026), ECF No. 1.
  2. Ctrs. for Medicare & Medicaid Servs., 2027 Medicare Advantage and Part D Star Ratings, Changes in the Methodology for the 2027 Star Ratings (Oct. 8, 2026).
  3. CVS Health Corp. v. Dep’t of Health & Hum. Servs., No. 2:26-cv-00115, Docket Report (S.D. Ga., retrieved Oct. 26, 2026) (public copy on Justia).
  4. Ctrs. for Medicare & Medicaid Servs., 2027 Star Ratings Measures and Weights, tbl. 2.