⚠ Stars Are Re-Scored Every YearModerate threat

UnitedHealth Group (UNH) — threat to the moat

Humana lost a fifth of its four-star membership in one re-scoring; UnitedHealthcare's lead has to survive the same test every year.

A star rating is not a permanent asset. The government re-scores plans every year, and for 2026 several leading insurers slipped amid more stringent requirements1. Aetna's share of members in four-star plans fell from 88% to 81%, and Humana's from 25% to 20%2.

Change in share of MA members in 4-star plans, 2025 to 2026 star year (points)-7 (to 81%)Aetna+3 (to 78%)UnitedHealthcare-5 (to 20%)HumanaFierce Healthcare, 2026 Medicare Advantage star ratings
Two rivals fell; UnitedHealthcare rose.

UnitedHealthcare went the other way, from 75% to 78%3, and said it has "more members in plans rated 4-star or higher than any other carrier in the industry"4. That is a strong position, but it is re-earned each autumn.

The stakes are large because the Medicare book is large: Medicare & Retirement revenue was $171,285 million in 20255. A fall below four stars on a big contract reduces payments for a whole year.

The industry average barely moved: 64% of Medicare Advantage enrollees were in plans with four or more stars, on par with the year before6. So the tighter rules did not lower the average; they redistributed it, taking members out of four-star plans at some insurers and into them at others. More than 63% of Aetna's members were in plans rated at least 4.5 stars7.

The next star release is the thing to read. A drop in UnitedHealthcare's four-star share of more than a few points would say the tighter rules have caught up with it as they did with Humana.

References
  1. ReportedThe government re-scores plans every year, and for 2026 several leading insurers slipped amid more stringent requirements.
    Fierce Healthcare, '2026 MA Star Ratings: Aetna, Humana see scores decline; UnitedHealthcare improves'. — October 2025 · publ. 10 October 2025 · source ↗
  2. ReportedAetna's share of members in four-star plans fell from 88% to 81%, and Humana's from 25% to 20%.
    Fierce Healthcare, '2026 MA Star Ratings: Aetna, Humana see scores decline; UnitedHealthcare improves'. — October 2025 · publ. 10 October 2025 · source ↗
  3. ReportedUnitedHealthcare went the other way, from 75% to 78%, and said it has "more members in plans rated 4-star or higher than any other carrier in the industry".
    Fierce Healthcare, '2026 MA Star Ratings: Aetna, Humana see scores decline; UnitedHealthcare improves'. — October 2025 · publ. 10 October 2025 · source ↗
  4. ReportedUnitedHealthcare went the other way, from 75% to 78%, and said it has "more members in plans rated 4-star or higher than any other carrier in the industry".
    Fierce Healthcare, '2026 MA Star Ratings: Aetna, Humana see scores decline; UnitedHealthcare improves'. — October 2025 · publ. 10 October 2025 · source ↗
  5. ReportedThe stakes are large because the Medicare book is large: Medicare & Retirement revenue was $171,285 million in 2025.
    UnitedHealth Group Form 10-K for fiscal 2025 - Item 7 MD&A: consolidated and segment results, medical care ratio, membership and operating metrics. — FY2025 · publ. 2 March 2026 · source ↗
  6. ReportedThe industry average barely moved: 64% of Medicare Advantage enrollees were in plans with four or more stars, on par with the year before.
    Fierce Healthcare, '2026 MA Star Ratings: Aetna, Humana see scores decline; UnitedHealthcare improves'. — October 2025 · publ. 10 October 2025 · source ↗
  7. ReportedMore than 63% of Aetna's members were in plans rated at least 4.5 stars.
    Fierce Healthcare, '2026 MA Star Ratings: Aetna, Humana see scores decline; UnitedHealthcare improves'. — October 2025 · publ. 10 October 2025 · source ↗
Sources
Generated September 26, 2026