Investigations · Carrier Reviews

The 2026 Medicare Carrier Audit

Every year we score the largest national Medicare Advantage and Medigap carriers on CMS Star Rating, prior-authorization denial rates, appeal-overturn rates and enrolled-life complaint volume — weighted toward what actually affects beneficiaries.

Investigations Desk · Updated this quarter · 14 min read

Methodology

· CMS Star Ratings (published each October).
· CMS Complaint Tracking Module data, normalized per 1,000 enrolled lives.
· Prior-authorization denial rate and overturn-on-appeal rate from CMS Medicare Advantage reporting.
· State Department of Insurance market conduct exams for Medigap financial strength.

Medicare Advantage

Kaiser Permanente

Grade: A

Star Rating: 4.5

Enrolled lives: 1.9M

PA denial rate: 4.8%

Overturn on appeal: 82%

What works

· Highest average Star Rating among national carriers.
· Integrated delivery model — care and coverage under one roof.
· Low prior-authorization denial rate relative to peers.

What to watch

· Available only in 8 states plus D.C.
· Closed network with no meaningful out-of-network coverage.

Bottom line — The strongest MA option where available. Geographic limits are the story.

Medicare Advantage

Humana

Grade: A−

Star Rating: 4.0

Enrolled lives: 5.7M

PA denial rate: 6.9%

Overturn on appeal: 78%

What works

· Broad national footprint with strong rural PPO presence.
· Consistent Star Rating performance across contracts.
· Dental and vision benefits above the peer median.

What to watch

· Provider network churn in select metro areas.
· Formulary changes mid-year have drawn CMS attention.

Bottom line — One of the most reliable MA carriers for beneficiaries who value plan stability.

Both

UnitedHealthcare (AARP)

Grade: B+

Star Rating: 4.0

Enrolled lives: 9.1M

PA denial rate: 9.1%

Overturn on appeal: 76%

What works

· Largest MA and Medigap footprint in the country.
· AARP-branded Medigap plans offer household discounts in many states.
· Deep pharmacy benefit integration through OptumRx.

What to watch

· Prior-authorization volume above peer median (subject of a 2024 Senate report).
· Provider network disputes in Texas, California and the Northeast.

Bottom line — Scale and reach come with a heavier utilization-management footprint.

Both

Aetna (CVS Health)

Grade: B

Star Rating: 3.5

Enrolled lives: 4.2M

PA denial rate: 8.6%

Overturn on appeal: 72%

What works

· Strong integration with CVS retail pharmacies and MinuteClinic.
· Solid PPO options in most states.

What to watch

· Star Ratings slipped in the 2024 and 2025 measurement years.
· Extra benefits weighted toward CVS-owned assets.

Bottom line — Best fit for enrollees who already use CVS/Aetna's owned pharmacy and clinic network.

Medicare Advantage

Cigna Healthcare

Grade: B

Star Rating: 3.5

Enrolled lives: 0.7M

PA denial rate: 7.4%

Overturn on appeal: 74%

What works

· Competitive premium positioning in Southeastern and Sunbelt markets.
· Improving Star Ratings trend.

What to watch

· Smaller network than the top-three carriers.
· Divestiture history has caused member-facing disruption.

Bottom line — Regionally competitive; confirm your providers before enrolling.

Both

Blue Cross Blue Shield (regional)

Grade: B

Star Rating: 3.5

Enrolled lives: 3.9M

PA denial rate: 8.2%

Overturn on appeal: 70%

What works

· Strong local provider relationships in most states.
· Medigap community rating in a handful of Blue states holds premiums flat with age.

What to watch

· Quality varies substantially by state licensee.
· Some plans have unusually strict prior-authorization rules.

Bottom line — Judge the specific state Blue plan — not the national brand.

Medigap

Mutual of Omaha

Grade: A−

Star Rating: —

Enrolled lives: 1.6M

PA denial rate: —

Overturn on appeal: —

What works

· Consistently priced Plan G and Plan N.
· Household discount available in most states.
· A+ AM Best financial strength rating.

What to watch

· No Medicare Advantage offering to bundle with.
· Rate history reviews show attained-age structure — premiums rise with age.

Bottom line — A default shortlist for Medigap shoppers who don't need an MA option.

Medigap

Cigna (Loyal American / American Retirement Life)

Grade: B+

Star Rating: —

Enrolled lives: 1.1M

PA denial rate: —

Overturn on appeal: —

What works

· Aggressive Plan G pricing in newer entry markets.
· Solid underwriting decisions for standard-health applicants.

What to watch

· Rate history in some states shows above-average annual increases.
· Brand confusion between Cigna Health and Cigna Medigap subsidiaries.

Bottom line — Worth quoting alongside Mutual of Omaha and UnitedHealthcare/AARP.