Medicare Advantage in Williamson County, IL, for 2027.
CMS lists 9 Medicare Advantage plans here for 2027, 9 fewer than 2026 (18). 5,562 people in the county had an individual Medicare Advantage plan in October 2026.
Sources: CMS CY2027 plan file (October 2026 release), CMS CY2026 plan file (September 2026 release), CMS enrollment by county (CPSC), October 2026, CMS 2027 Plan Crosswalk (October 1, 2026), CMS 2027 Star Ratings Data Tables (October 8, 2026). Member counts are floors because CMS hides counts of 10 or fewer.
The county in numbers
Plans that end here for 2027
8 plans with members in the county end or leave it, plus 20 with 10 or fewer members here. CMS moves 349 members to another plan, and 1,140 stay in the same plan.
| Plan | Insurer | Members | Why |
|---|---|---|---|
| Aetna Medicare Signature (PPO) | CVS Health | 574 | Plan terminated |
| HealthSpring True Choice (PPO) | Health Care Service | 479 | Plan terminated |
| Blue Cross Medicare Advantage Essential (PPO) | Health Care Service | 165 | Plan terminated |
| Blue Cross Medicare Advantage Dental Premier (PPO) | Health Care Service | 103 | Plan terminated |
| Blue Cross Medicare Advantage Health Choice (PPO) | Health Care Service | 73 | Plan terminated |
| Aetna Medicare Eagle (PPO) | CVS Health | 60 | Plan leaves this county |
| Aetna Medicare Enhanced (PPO) | CVS Health | 41 | Plan terminated |
| Wellcare Patriot Giveback (HMO) | Centene | 27 | Plan terminated |
Where CMS moves members
| 2026 plan | 2027 plan | Members |
|---|---|---|
| Molina Medicare Complete Care Plus (HMO D-SNP) | Molina Medicare Complete Care Plus (HMO D-SNP) | 215 |
| Wellcare Simple Essential (HMO) | Wellcare Simple Essential (HMO) | 134 |
Who holds the members
- CVS Health3,313
- Health Care Service833
- Humana573
- Centene500
- Molina Healthcare215
- UnitedHealth128
Individual Medicare Advantage members by parent company, October 2026.
Top rated plans sold here
No plan sold here has a 2027 overall rating of 4.5 or more.
2027 overall Star Rating, 4.5 or more. Each plan's measure stars are in the county lookup.
See every plan, premium and copay in the free lookup.
Sort all 9 plans, open each plan's benefits and star measures, and see what each insurer paid agents in 2026.
Open Williamson in the lookupWorking this county for AEP?
The AEP 2027 County Kit puts this county and your others in one file: the plans that end, where members land, what is still sold and a crosswalk sheet, with every number tied to its CMS file.
See the AEP 2027 County KitAll Illinois county pages. Facts from public CMS files, prepared by Health and Tech Now. Not plan advice. Check a plan's Summary of Benefits before you enroll.