UnitedHealth in Illinois: 169,348 Medicare Advantage members, 20.9% share, 3rd of 11.
UnitedHealth Group, Inc., shown as UnitedHealth, lost 1,412 members (−0.8%) from Nov 2025 to Oct 2026 and stepped −3.2% at the 2026 election period against the market's +8.0%. It sells in 100 of Illinois’s 102 counties with visible members and leads 32; Aetna (CVS) sits just ahead at 21.5%, Health Care Service Corporation just behind at 6.5%.
UnitedHealth's twelve months in Illinois
Visible members each month, Nov 2025 to Oct 2026. The December-to-January step is the election period. The market line for the state is on the Illinois page.
Where UnitedHealth's Illinois members are
The carrier’s five largest counties by visible members, with its share of each county’s visible Medicare Advantage members. It sells in 100 counties and leads 32 of them.
| County | UnitedHealth members | Share of county | County visible members | County leader |
|---|---|---|---|---|
| Cook | 58,838 | 17.9% | 327,723 | Humana |
| Madison | 12,075 | 47.1% | 25,645 | UnitedHealth |
| St. Clair | 11,605 | 45.9% | 25,265 | UnitedHealth |
| DuPage | 8,328 | 15.9% | 52,312 | Humana |
| Lake | 7,411 | 21.1% | 35,036 | Humana |
UnitedHealth against the Illinois market
The carrier’s figures beside the state’s, each weighted by members. A difference is a difference, not a grade: a higher maximum or a lower rating is a design and a result, read in context.
top three hold 79.6%
market 3.91, +0.07, 2nd of 6 rated
market 88%, −8 points
market $5,000, +$2,150
| # | Carrier | Members | Share | Twelve months | Election step | Counties led | Rating | $0 premium |
|---|---|---|---|---|---|---|---|---|
| 1 | Humana | 300,815 | 37.2% | +34.6% | +25.3% | 30 of 101 | 4.10 | 99% |
| 2 | Aetna (CVS) | 173,848 | 21.5% | +10.1% | +5.6% | 40 of 102 | 3.96 | 75% |
| 3 | UnitedHealth | 169,348 | 20.9% | −0.8% | −3.2% | 32 of 100 | 3.98 | 79% |
| 4 | Health Care Service Corporation | 52,590 | 6.5% | −16.0% | −14.9% | 0 of 63 | 3.15 | 61% |
| 5 | Centene | 47,722 | 5.9% | +36.4% | +32.2% | 0 of 89 | 3.19 | 100% |
| 6 | Zing Health Consolidator, Inc | 19,412 | 2.4% | +12.2% | −7.8% | 0 of 12 | 3.50 | 100% |
What 2027 does to UnitedHealth's plans in Illinois
The fate assigned to each of the carrier’s plans for 2027, joined to the members in it today.
2,007 members are in 1 plan that end and must choose again. 30,276 members are in 6 plans that drop at least one county; which counties is not stated. In all, 19% of UnitedHealth’s Illinois members are in a plan whose service area or status changes.
The read on UnitedHealth in Illinois is in Carrier Command.
Risk and rebate against the market, the five-test read on coding versus selection, Stars levers and next year's cut points, the election-period forecast and the county-by-county standing, written as a monthly page.
UnitedHealth elsewhere, and the rest of Illinois
- Humana37.2%
- Aetna (CVS)21.5%
- Health Care Service Corporation6.5%
- Centene5.9%
- Zing Health Consolidator, Inc2.4%
How these numbers are made
- Members are visible members: CMS suppresses any plan-county cell of ten or fewer, so small counties undercount. Market share excludes employer group plans.
- Enrollment is Oct 2026; the twelve months run Nov 2025 to Oct 2026; the election step compares December 2025 with January 2026.
- UnitedHealth is the parent organization UnitedHealth Group, Inc.; its 23 plans in Illinois may sell under other brand names. The rating is the 2027 overall Star Rating of its contracts weighted by members in Illinois; $0 premium and the in-network maximum are the 2027 filings weighted by members today.
- Plan fates are the ones assigned for contract year 2027.
- Every figure comes from public CMS data as Livmor reads it, and the page is rebuilt when a new month posts. Livmor Carrier Command, public CMS data.