MA Enrollment Explorer / States / Idaho
Medicare Advantage in Idaho: enrollment, penetration and market share
192,412 people in Idaho were enrolled in Medicare Advantage in October 2026. 45.8% of the state's 420,240 eligible Medicare beneficiaries are in Medicare Advantage, −4.6 pts since October 2025. UnitedHealth Group, Inc. is the largest parent organization with 42% of reported enrollment; 16 parent organizations have 11 or more members, and the market's HHI is 2,485 (highly concentrated). Through the 2026 Annual Election Period (December to February), reported MA enrollment in Idaho changed by −17,951 (−8.8%).
45.8%MA penetration, October 2026
192KMA enrollees
16parent organizations (11+ members)
2,485HHI, highly concentrated
Parent organizations in Idaho
| Parent organization | Members | Change | Share | Share change |
|---|---|---|---|---|
| UnitedHealth Group, Inc. | 80,688 | +4,631 | 42.3% | +4.9 pts |
| Gemstone Holdings, Inc. | 36,130 | −41,393 | 18.9% | −19.2 pts |
| Trinity Health Corporation | 22,894 | +19,024 | 12.0% | +10.1 pts |
| PacificSource | 17,069 | +7,300 | 8.9% | +4.1 pts |
| Humana Inc. | 15,695 | +5,759 | 8.2% | +3.3 pts |
| Molina Healthcare, Inc. | 12,918 | −1,023 | 6.8% | −0.1 pts |
| CVS Health Corporation | 2,252 | +62 | 1.2% | +0.1 pts |
| Elevance Health, Inc. | 893 | +20 | 0.5% | +0.04 pts |
| Cambia Health Solutions, Inc. | 796 | −6,657 | 0.4% | −3.2 pts |
| Fenyx Health Holdings, Inc. | 751 | +740 | 0.4% | +0.4 pts |
| California Physicians' Service | 335 | +32 | 0.2% | +0.03 pts |
| Mitchell Family Office | 244 | +146 | 0.1% | +0.1 pts |
| Highmark Health | 70 | +14 | under 0.1% | +0.01 pts |
| Blue Cross Blue Shield of Michigan Mutual Ins. Co. | 64 | 0 | under 0.1% | +0.00 pts |
| Health Care Service Corporation | 32 | −1 | under 0.1% | +0.00 pts |
| Kaiser Foundation Health Plan, Inc. | 16 | −20 | under 0.1% | −0.01 pts |
Change and share change are since October 2025. Shares are of reported enrollment in the CMS State/County/Contract file.