2027 open enrollment. 3.15 million people must pick a new Medicare Advantage plan. See every plan and county, free.3.15M must pick a new plan.
Look up your countyYour county →Vlada / Medicare Advantage / Montana
Medicare Advantage plan exits 2027 in Montana, by county
18,554 of Montana's 73,154 Medicare Advantage members (25.4%) are in a plan that is not sold in their county for 2027, measured from the CMS 2027 Landscape and crosswalk against September 2026 enrollment. Nationally the share is 10.6%.
Period: plan year 2027 against September 2026 members · Updated 2026-10-19 · Next: CMS January 2027 enrollment (February 2027): where the members landed
- members, Sept 2026
- 73,154
- members, Sept 2026
- must pick for 2027
- 18,554
- must pick for 2027
- share of members
- 25.4%
- share of members
- counties
- 49
- counties
Members who must pick a new plan each year, 2016 to 2027
Members of individual Medicare Advantage plans in Montana whose plan is not sold in their county the next year, by plan year; the share of all members at the top of each bar. Orange: the last three years.
Every Montana county, 2027
Members in September 2026; those whose plan is not sold in their county for 2027; their share; of those, the members offered a new or renumbered plan by their own company in the county, and the members whose company sells no plan there for 2027. Sorted by members who must pick. Each county links to its own page: the plans that end, the companies, enrollment and penetration since 2015, the Stars.
| County | Members, Sept 2026 | Must pick for 2027 | Share | Offered a new or renumbered plan | Company gone |
|---|---|---|---|---|---|
| Yellowstone | 13,484 | 3,913 | 29.0% | 0 | 2,431 |
| Flathead | 9,296 | 2,557 | 27.5% | 0 | 1,404 |
| Gallatin | 4,730 | 1,993 | 42.1% | 0 | 1,993 |
| Ravalli | 4,402 | 1,551 | 35.2% | 0 | 1,551 |
| Missoula | 6,212 | 1,548 | 24.9% | 0 | 1,548 |
| Cascade | 7,123 | 1,157 | 16.2% | 0 | 1,157 |
| Lake | 2,259 | 1,052 | 46.6% | 70 | 715 |
| Lewis and Clark | 5,060 | 665 | 13.1% | 0 | 665 |
| Lincoln | 3,249 | 599 | 18.4% | 0 | 599 |
| Stillwater | 867 | 471 | 54.3% | 0 | 20 |
| Custer | 344 | 344 | 100.0% | 0 | 344 |
| Fergus | 1,129 | 305 | 27.0% | 0 | 305 |
| Chouteau | 316 | 219 | 69.3% | 0 | 18 |
| Hill | 209 | 209 | 100.0% | 0 | 209 |
| Sanders | 1,533 | 205 | 13.4% | 0 | 205 |
| Teton | 604 | 179 | 29.6% | 0 | 0 |
| Beaverhead | 549 | 161 | 29.3% | 0 | 161 |
| Park | 805 | 150 | 18.6% | 0 | 99 |
| Silver Bow | 2,448 | 148 | 6.0% | 0 | 148 |
| Madison | 515 | 137 | 26.6% | 0 | 137 |
| Big Horn | 608 | 114 | 18.8% | 0 | 0 |
| Mineral | 498 | 110 | 22.1% | 0 | 110 |
| Glacier | 442 | 101 | 22.9% | 0 | 15 |
| Powell | 334 | 100 | 29.9% | 0 | 100 |
| Sweet Grass | 255 | 97 | 38.0% | 0 | 97 |
| Deer Lodge | 675 | 62 | 9.2% | 0 | 62 |
| Jefferson | 1,031 | 61 | 5.9% | 0 | 61 |
| Carbon | 970 | 56 | 5.8% | 0 | 56 |
| Pondera | 409 | 43 | 10.5% | 0 | 43 |
| Musselshell | 561 | 39 | 7.0% | 0 | 39 |
| Judith Basin | 213 | 38 | 17.8% | 0 | 38 |
| Broadwater | 504 | 36 | 7.1% | 0 | 36 |
| Wheatland | 184 | 31 | 16.8% | 0 | 31 |
| Granite | 185 | 25 | 13.5% | 0 | 25 |
| Golden Valley | 104 | 25 | 24.0% | 0 | 0 |
| McCone | 23 | 23 | 100.0% | 0 | 23 |
| Rosebud | 364 | 18 | 4.9% | 0 | 18 |
| Toole | 140 | 12 | 8.6% | 0 | 12 |
| Valley | 93 | 0 | 0.0% | 0 | 0 |
| Roosevelt | 74 | 0 | 0.0% | 0 | 0 |
| Phillips | 72 | 0 | 0.0% | 0 | 0 |
| Treasure | 71 | 0 | 0.0% | 0 | 0 |
| Liberty | 67 | 0 | 0.0% | 0 | 0 |
| Meagher | 57 | 0 | 0.0% | 0 | 0 |
| Powder River | 27 | 0 | 0.0% | 0 | 0 |
| Fallon | 19 | 0 | 0.0% | 0 | 0 |
| Prairie | 17 | 0 | 0.0% | 0 | 0 |
| Daniels | 12 | 0 | 0.0% | 0 | 0 |
| Petroleum | 11 | 0 | 0.0% | 0 | 0 |
| Montana, 49 counties | 73,154 | 18,554 | 25.4% | 70 | 14,475 |
Download this table (CSV, CC BY 4.0) · cells under 11 members are suppressed by CMS and count as zero, so every count is a floor.
Montana against the nation
| Measure | Montana | United States |
|---|---|---|
| Must pick a new plan for 2027 | 18,554 | 3,153,512 |
| Share of members | 25.4% | 10.6% |
| Share for 2026 | 14.0% | 10.1% |
National figures: the Vlada report 3.15 million Medicare Advantage members must pick a new plan for 2027.
Star Ratings 2027, member-weighted
| Measure | 2027 | 2026 | Change |
|---|---|---|---|
| Members in contracts rated 4+ stars | 93.3% | 19.8% | +73.5 pts |
| Member-weighted average star | 4.03 | 3.67 | +0.36 |
| Rated contracts | 16 |
Members by star, 2027: 4.5: 15,404 · 4.0: 57,232 · 3.5: 30 · 3.0: 4,795 · 2.5: 393; 0 in unrated contracts. CMS Star Ratings released 2026-10-08, each contract's overall star weighted by its 2026-10 members in Montana (individual and group); rating year 2027 pays in 2028.
By company, 2027
CMS parent organizations with members in Montana in September 2026: members whose plan is not sold in their county for 2027, as a share of the company's own members; how the plan went (terminated, or its service area reduced so it continues elsewhere but not in their county); of those members, how many the company offers a new or renumbered plan of the same type in the county, and how many are left with no plan from the company there.
| Company | Members | Must pick | Share of own members | Plan terminated | Service area reduced | Offered a new or renumbered plan | Company gone |
|---|---|---|---|---|---|---|---|
| Health Care Service Corporation | 12,684 | 12,684 | 100.0% | 12,684 | 0 | 0 | 12,684 |
| UnitedHealth Group, Inc. | 5,153 | 3,727 | 72.3% | 3,727 | 0 | 0 | 688 |
| PacificSource | 1,103 | 1,103 | 100.0% | 1,103 | 0 | 0 | 1,103 |
| Humana Inc. | 54,214 | 1,040 | 1.9% | 0 | 1,040 | 70 | 0 |
Sources
- CMS Medicare Advantage/Part D Landscape, plan year 2027: landscape_cy2027-landscape-202609-1.zip (CMS, September 2026).
- CMS plan crosswalk, CY2027; CMS monthly enrollment by contract, plan and county, 2026-09.
- CMS Star Ratings 2027, released 2026-10-08.
- Page object written 2026-10-19; the series 2016 to 2027 from the locked exits history of the Vlada report (independent audit 2026-10-13).
Receipts: athena(table=medicare_semantic.exits_cells_county_2027_v1, block=counties) bce72deb8c12…; athena(table=medicare_semantic.exits_cells_county_2027_v1, block=companies) 15de170f7bb5…; get_stars_rollup(group_by=state, limit=60) 2c1fa6b01add…; file(path=docs/research/plan-exits-2027/data/audited/by_year_state.csv) b2f25ce9152e…. Suppressed cells (under 11 members) count as zero in every count.
Cite: Vlada Health (2026). Medicare Advantage plan exits 2027 in Montana, by county. https://www.vladahealth.com/medicare-advantage/mt. Data: CC BY 4.0.
Method
- Population: members of individual Medicare Advantage plans (H and R contracts, plans 001 to 799, special needs plans included; employer group, Cost, MMP and PACE excluded) in the county in September 2026.
- Must pick: the CMS crosswalk names no successor plan sold in the member's county for 2027; members CMS moves to a successor in their county are not counted.
- Company: CMS's reported parent organization in September 2026; a company's share is over its own members in the state.
- Stars: each contract's overall star weighted by its members in Montana; unrated contracts counted apart, never as zero stars.
- Suppression: CMS hides cells under 11 members; they count as zero, so every count is a floor and every share is not.
The full method, with the national tables: How we counted, and how to check it.
Questions
- How many Medicare Advantage members in Montana must pick a new plan for 2027?
- 18,554 of 73,154 members (25.4%): their plan is not sold in their county for 2027 according to the CMS crosswalk and Landscape. Nationally the share is 10.6% (3,153,512 members).
- Which Montana county has the most members who must pick?
- Yellowstone County: 3,913 of 13,484 members (29.0%). 3 of the 49 counties lose 90% or more of their members' plans; 11 lose none.
- Which company ended the most plans in Montana for 2027?
- Health Care Service Corporation: 12,684 of its 12,684 Montana members (100.0%) are in a plan it does not sell in their county for 2027.
- How did Montana's Star Ratings change for 2027?
- 93.3% of members are in contracts rated 4 stars or more for 2027, against 19.8% the year before; the member-weighted average star is 4.03, from 3.67, over 16 rated contracts.
- How does 2027 compare with 2026 in Montana?
- 10,072 members (14.0%) had to pick a new plan for 2026; for 2027 it is 18,554 (25.4%), a change of +8,482 members.
Ask this in Claude or ChatGPT
The free Vlada connector answers it from the same files, with the source and a response hash. Install in one minute.
Use Vlada. Which Montana counties have the most Medicare Advantage members who must pick a new plan for 2027? Give me a table with the members in the market, the members who lose their plan and the share, then the source file, the data vintage and the response hash.
Behind it: get_landscape_exits (transition_year 2026, group_by county, state MT) and get_stars_rollup (group_by state).