MA Enrollment Explorer / States / Montana
Medicare Advantage in Montana: enrollment, penetration and market share
81,059 people in Montana were enrolled in Medicare Advantage in October 2026. 29.5% of the state's 274,432 eligible Medicare beneficiaries are in Medicare Advantage, −0.4 pts since October 2025. Humana Inc. is the largest parent organization with 69% of reported enrollment; 11 parent organizations have 11 or more members, and the market's HHI is 5,204 (highly concentrated). Through the 2026 Annual Election Period (December to February), reported MA enrollment in Montana changed by −109 (−0.1%).
29.5%MA penetration, October 2026
81KMA enrollees
11parent organizations (11+ members)
5,204HHI, highly concentrated
Parent organizations in Montana
| Parent organization | Members | Change | Share | Share change |
|---|---|---|---|---|
| Humana Inc. | 55,451 | +12,061 | 69.4% | +14.6 pts |
| Health Care Service Corporation | 13,764 | −4,268 | 17.2% | −5.5 pts |
| UnitedHealth Group, Inc. | 7,690 | −7,186 | 9.6% | −9.2 pts |
| CVS Health Corporation | 1,443 | +9 | 1.8% | −0.00 pts |
| PacificSource | 1,099 | +125 | 1.4% | +0.1 pts |
| Elevance Health, Inc. | 309 | −7 | 0.4% | −0.01 pts |
| California Physicians' Service | 70 | +12 | under 0.1% | +0.01 pts |
| Blue Cross Blue Shield of Michigan Mutual Ins. Co. | 46 | −9 | under 0.1% | −0.01 pts |
| Cambia Health Solutions, Inc. | 35 | −20 | under 0.1% | −0.03 pts |
| UMWA Health and Retirement Funds | 32 | −1 | under 0.1% | −0.00 pts |
| Aware Integrated, Inc. | 19 | 0 | under 0.1% | −0.00 pts |
Change and share change are since October 2025. Shares are of reported enrollment in the CMS State/County/Contract file.