Free tool · public CMS data
Montana Medicare Advantage market share
In September 2026, 77,821 Montana Medicare beneficiaries were enrolled in a Medicare Advantage plan across 63 parent carriers and 56 counties, led by Humana Inc. with 70.3% of counted enrollment.
Data month
September 2026
Advantage enrollees
77,821
+1.2% vs September 2025
Parent carriers
63
Advantage penetration
29.5%
CMS Medicare Monthly Enrollment, 2024
Carriers in Montana
CMS Monthly Enrollment by Contract/Plan/State/County (CPSC) · September 2026
| # | Parent organisation | Enrollees | Share | Counties | vs September 2025 |
|---|---|---|---|---|---|
| 1 | Humana Inc. | 54,688 | 70.3% | 56 | +27.7% |
| 2 | Health Care Service Corporation | 13,300 | 17.1% | 56 | -24.6% |
| 3 | UnitedHealth Group, Inc. | 7,092 | 9.1% | 56 | -49.1% |
| 4 | CVS Health Corporation | 1,253 | 1.6% | 56 | +1.5% |
| 5 | PacificSource | 1,103 | 1.4% | 56 | +14.1% |
| 6 | Elevance Health, Inc. | 237 | 0.3% | 56 | +12.3% |
| 7 | California Physicians' Service | 68 | 0.1% | 56 | +19.3% |
| 8 | Blue Cross Blue Shield of Michigan Mutual Ins. Co. | 33 | 0.0% | 56 | +10.0% |
| 9 | Cambia Health Solutions, Inc. | 30 | 0.0% | 56 | -11.8% |
| 10 | Aware Integrated, Inc. | 17 | 0.0% | 56 | -5.6% |
| 11 | Alignment Healthcare USA, LLC | 0 | 0.0% | 56 | — |
| 12 | Allina Health and Aetna Insurance Holding Company | 0 | 0.0% | 56 | — |
| 13 | ATRIO Health Plans | 0 | 0.0% | 3 | — |
| 14 | Aultman Health Foundation | 0 | 0.0% | 56 | — |
| 15 | BayCare Health System, Inc. | 0 | 0.0% | 1 | — |
| 16 | Baystate Health, Inc. | 0 | 0.0% | 56 | — |
| 17 | Blue Cross & Blue Shield of Rhode Island | 0 | 0.0% | 56 | — |
| 18 | Blue Cross and Blue Shield of Massachusetts, Inc. | 0 | 0.0% | 56 | — |
| 19 | Blue Cross Blue Shield of Arizona | 0 | 0.0% | 1 | — |
| 20 | Blue Cross Blue Shield of Kansas | 0 | 0.0% | 56 | — |
| 21 | Blue Cross Blue Shield of Nebraska | 0 | 0.0% | 56 | — |
| 22 | BlueCross BlueShield of Alabama | 0 | 0.0% | 56 | — |
| 23 | BlueCross BlueShield of South Carolina (BCBSSC) | 0 | 0.0% | 56 | — |
| 24 | BlueCross BlueShield of Tennessee | 0 | 0.0% | 56 | — |
| 25 | CAPITAL BLUE CROSS | 0 | 0.0% | 56 | — |
| 26 | CareFirst, Inc. | 0 | 0.0% | 56 | — |
| 27 | Centene Corporation | 0 | 0.0% | 7 | — |
| 28 | Corewell Health | 0 | 0.0% | 56 | — |
| 29 | CuraCor Solutions Corp. | 0 | 0.0% | 56 | — |
| 30 | Devoted Health, Inc. | 0 | 0.0% | 5 | — |
| 31 | EmblemHealth, Inc. | 0 | 0.0% | 56 | — |
| 32 | Fallon Community Health Plan, Inc. | 0 | 0.0% | 56 | — |
| 33 | Fenyx Health Holdings, Inc. | 0 | 0.0% | 56 | — |
| 34 | General Catalyst Group Management Holdings LP | 0 | 0.0% | 56 | — |
| 35 | Guidewell Mutual Holding Corporation | 0 | 0.0% | 56 | — |
| 36 | Hawaii Medical Service Association | 0 | 0.0% | 56 | — |
| 37 | Healthfirst, Inc. | 0 | 0.0% | 56 | — |
| 38 | HealthPartners, Inc. | 0 | 0.0% | 56 | — |
| 39 | Henry Ford Health System | 0 | 0.0% | 56 | — |
| 40 | Highmark Health | 0 | 0.0% | 56 | — |
| 41 | Horizon Mutual Holdings, Inc | 0 | 0.0% | 56 | — |
| 42 | Imperial Health Plan of California | 0 | 0.0% | 3 | — |
| 43 | Independence Health Group, Inc. | 0 | 0.0% | 56 | — |
| 44 | Independent Health Association, Inc. | 0 | 0.0% | 56 | — |
| 45 | Intermountain Health Care, Inc. | 0 | 0.0% | 2 | — |
| 46 | Kaiser Foundation Health Plan, Inc. | 0 | 0.0% | 13 | — |
| 47 | Lifetime Healthcare, Inc. | 0 | 0.0% | 56 | — |
| 48 | Longevity Health Founders, LLC | 0 | 0.0% | 1 | — |
| 49 | Louisiana Health Service & Indemnity Company | 0 | 0.0% | 56 | — |
| 50 | Martin's Point Health Care, Inc. | 0 | 0.0% | 56 | — |
| 51 | Medica Holding Company | 0 | 0.0% | 56 | — |
| 52 | MEDICAL MUTUAL OF OHIO | 0 | 0.0% | 56 | — |
| 53 | Molina Healthcare, Inc. | 0 | 0.0% | 3 | — |
| 54 | MVP Health Care, Inc. | 0 | 0.0% | 56 | — |
| 55 | Network Health, Inc. | 0 | 0.0% | 56 | — |
| 56 | Orange County Health Authority | 0 | 0.0% | 1 | — |
| 57 | Providence St Joseph Health | 0 | 0.0% | 1 | — |
| 58 | Sanford Health | 0 | 0.0% | 2 | — |
| 59 | SCAN Group | 0 | 0.0% | 4 | — |
| 60 | Sharp Healthcare | 0 | 0.0% | 2 | — |
| 61 | The Health Plan of West Virginia, Inc. | 0 | 0.0% | 56 | — |
| 62 | UPMC Health System | 0 | 0.0% | 56 | — |
| 63 | USAble Mutual Insurance Company | 0 | 0.0% | 56 | — |
County view
Leading carrier and Advantage enrollment in each Montana county. Penetration is from CMS Medicare Monthly Enrollment, 2024.
| County | Advantage enrollees | Leading carrier | Leader share | Carriers | Penetration |
|---|---|---|---|---|---|
| Yellowstone | 14,491 | Humana Inc. | 63.5% | 54 | 36.4% |
| Flathead | 9,983 | Humana Inc. | 65.6% | 51 | 33.8% |
| Cascade | 7,525 | Humana Inc. | 77.7% | 49 | 36.3% |
| Missoula | 6,684 | Humana Inc. | 70.9% | 53 | 27.2% |
| Lewis and Clark | 5,417 | Humana Inc. | 81.7% | 51 | 29.4% |
| Gallatin | 5,324 | Humana Inc. | 50.8% | 53 | 27.3% |
| Ravalli | 4,877 | Humana Inc. | 59.2% | 53 | 32.5% |
| Lincoln | 3,379 | Humana Inc. | 79.0% | 49 | 43.0% |
| Silver Bow | 2,532 | Humana Inc. | 91.3% | 50 | 29.2% |
| Lake | 2,413 | Humana Inc. | 64.7% | 51 | 29.8% |
| Sanders | 1,612 | Humana Inc. | 83.3% | 51 | 33.1% |
| Fergus | 1,129 | Humana Inc. | 73.0% | 48 | 34.4% |
| Jefferson | 1,042 | Humana Inc. | 93.1% | 49 | 28.2% |
| Carbon | 1,007 | Humana Inc. | 90.8% | 48 | 33.5% |
| Stillwater | 898 | Humana Inc. | 94.3% | 49 | 34.9% |
| Park | 868 | Humana Inc. | 81.3% | 50 | 18.0% |
| Deer Lodge | 689 | Humana Inc. | 89.0% | 48 | 26.6% |
| Big Horn | 608 | Humana Inc. | 73.8% | 49 | 29.1% |
| Teton | 604 | Humana Inc. | 67.7% | 49 | 36.0% |
| Musselshell | 561 | Humana Inc. | 93.0% | 48 | 34.0% |
| Beaverhead | 549 | Humana Inc. | 70.7% | 50 | 25.6% |
| Madison | 542 | Humana Inc. | 69.7% | 49 | 20.9% |
| Broadwater | 504 | Humana Inc. | 92.9% | 48 | 30.6% |
| Mineral | 498 | Humana Inc. | 77.9% | 49 | 35.3% |
| Glacier | 442 | Humana Inc. | 63.3% | 48 | 13.0% |
| Pondera | 409 | Humana Inc. | 89.5% | 49 | 22.5% |
| Rosebud | 381 | Humana Inc. | 90.8% | 48 | 21.3% |
| Custer | 355 | Health Care Service Corporation | 100.0% | 48 | 15.1% |
| Powell | 334 | Humana Inc. | 70.1% | 48 | 22.9% |
| Chouteau | 316 | Humana Inc. | 94.3% | 49 | 25.6% |
| Sweet Grass | 255 | Humana Inc. | 62.0% | 48 | 29.0% |
| Judith Basin | 213 | Humana Inc. | 82.2% | 48 | 35.8% |
| Hill | 209 | Health Care Service Corporation | 100.0% | 48 | 6.4% |
| Granite | 185 | Humana Inc. | 86.5% | 48 | 28.7% |
| Wheatland | 184 | Humana Inc. | 83.2% | 48 | 32.8% |
| Toole | 155 | Humana Inc. | 82.6% | 48 | 13.6% |
| Golden Valley | 104 | Humana Inc. | 76.0% | 48 | 36.2% |
| Valley | 93 | UnitedHealth Group, Inc. | 100.0% | 48 | 7.0% |
| Roosevelt | 74 | UnitedHealth Group, Inc. | 100.0% | 48 | 4.8% |
| Phillips | 72 | UnitedHealth Group, Inc. | 100.0% | 48 | 6.8% |
| Treasure | 71 | Humana Inc. | 100.0% | 48 | 35.7% |
| Liberty | 67 | Humana Inc. | 100.0% | 48 | 14.9% |
| Meagher | 57 | Humana Inc. | 100.0% | 48 | 15.6% |
| Powder River | 27 | UnitedHealth Group, Inc. | 100.0% | 48 | 9.1% |
| McCone | 23 | UnitedHealth Group, Inc. | 100.0% | 48 | 5.1% |
| Fallon | 19 | UnitedHealth Group, Inc. | 100.0% | 48 | 5.0% |
| Prairie | 17 | UnitedHealth Group, Inc. | 100.0% | 48 | 7.6% |
| Daniels | 12 | UnitedHealth Group, Inc. | 100.0% | 48 | 4.5% |
| Petroleum | 11 | UnitedHealth Group, Inc. | 100.0% | 48 | 14.9% |
| Blaine | 0 | Alignment Healthcare USA, LLC | — | 48 | 2.4% |
| Carter | 0 | Alignment Healthcare USA, LLC | — | 48 | 8.6% |
| Dawson | 0 | Alignment Healthcare USA, LLC | — | 48 | 12.0% |
| Garfield | 0 | Alignment Healthcare USA, LLC | — | 48 | 4.6% |
| Richland | 0 | Alignment Healthcare USA, LLC | — | 48 | 7.9% |
| Sheridan | 0 | Alignment Healthcare USA, LLC | — | 48 | 10.5% |
| Wibaux | 0 | Alignment Healthcare USA, LLC | — | 48 | 9.7% |
What is missing
CMS suppresses any plan-county cell with fewer than 11 enrollees. Those enrollees are missing from these counts, so every figure is a floor, not an exact total.
What is counted
Counts cover Medicare Advantage contracts only (Local CCP, Regional CCP, PFFS and MSA). Standalone Part D drug plans, cost plans, HCPP and PACE contracts are excluded.
Source: CMS Monthly Enrollment by Contract/Plan/State/County (CPSC).