We checked UnitedHealth's Medicare Advantage cut against CMS files. A third of its PPO members left.

On Oct 13, UnitedHealth Group said the number of seniors it serves through Medicare Advantage “contracted by 935,000 since year-end 2025.” In the same day’s prepared remarks, the company said that in 2027 UnitedHealthcare “will continue to prioritize high-value HMO, chronic special needs and dual special needs offerings.”

We tested both statements against CMS’s public enrollment files. We pulled the Monthly Enrollment by Plan files for December 2025, January 2026 and September 2026 and matched every plan to CMS’s Special Needs Plan report. The total checks out. The mix mostly checks out. One piece does not.

The total matches

CMS counts 10,294,359 people in UnitedHealth Group Medicare Advantage plans in its December 2025 file and 9,343,856 in its September 2026 file. That is 950,503 fewer members, a drop of 9.23%.

The company’s own numbers sit close to that. Its 935,000 figure includes “programs serving complex populations included in Medicaid.” The Medicare Advantage line in its People Served table went from 8,445,000 on Dec. 31, 2025 to 7,605,000 on Sept. 30, 2026, a drop of 840,000. The company and CMS count members differently, so the figures will never match to the person.

All three show the same cut.

Almost all of it happened at once. UnitedHealth had 9,406,915 members in the January 2026 file, 887,444 fewer than in December. From January to September it lost another 63,059.

Where the members left

Source: CMS Monthly Enrollment by Plan and SNP Comprehensive Report, December 2025 and September 2026 files.

PPO plans lost 683,895 members, a third of the December count and 72% of the total drop. HMO plans gained 64,687 and chronic condition special needs plans gained 40,342. That is the shape the company described.

Dual eligible special needs plans are the exception. These plans are for people who have both Medicare and Medicaid, according to Medicare.gov. UnitedHealth named them as a priority, and its dual plans lost 143,307 members over the same months. They are still its second biggest plan type, at 2,272,975 members.

Same files, five biggest insurers

Source: CMS Monthly Enrollment by Plan, December 2025 and September 2026 files.

In the CMS files, Medicare Advantage as a whole grew by 773,171 members. Humana added 1,365,327, more than UnitedHealth lost. Humana’s PPO plans alone grew from 2,276,010 to 2,908,972.

UnitedHealth still runs the biggest Medicare Advantage business by far. Its share of all members fell from 29.25% in December 2025 to 25.98% in September 2026. Humana’s rose from 16.56% to 20.00%. CVS Health went from 11.92% to 11.59%.

How we counted

We count Medicare Advantage as CMS organization types Local CCP, Regional CCP, MSA and PFFS. Standalone drug plans, cost plans, PACE and demonstration plans are left out. Plan IDs 800 and up are employer group plans. A plan is a special needs plan when its contract and plan ID appear in CMS’s SNP Comprehensive Report for the same month.

CMS blanks out plans with 10 or fewer members, so every count here is a floor.

Our September 2026 dual eligible total for the whole market is 6,486,024, against 6,486,061 in CMS’s own SNP summary. We group insurers by the Parent Organization field in the CMS file. The Allina Health and Aetna joint venture is its own parent in that file and is not in the CVS Health count.

What it means for you

If you are in a UnitedHealthcare PPO, the files show that plan type is where the company is pulling back. Check your 2027 Annual Notice of Change before open enrollment ends on Dec. 7, 2026. If your plan is leaving your county, see what to do if your plan is leaving. For the whole market, see Medicare Advantage passes 36 million members.

This story reports public data. It is not insurance or enrollment advice. For help with your own coverage, call 1-800-MEDICARE or a free SHIP counselor.