Free tool · public CMS data
Idaho Medicare Advantage market share
In September 2026, 188,342 Idaho Medicare beneficiaries were enrolled in a Medicare Advantage plan across 73 parent carriers and 44 counties, led by UnitedHealth Group, Inc. with 42.3% of counted enrollment.
Data month
September 2026
Advantage enrollees
188,342
-6.0% vs September 2025
Parent carriers
73
Advantage penetration
48.6%
CMS Medicare Monthly Enrollment, 2024
Carriers in Idaho
CMS Monthly Enrollment by Contract/Plan/State/County (CPSC) · September 2026
| # | Parent organisation | Enrollees | Share | Counties | vs September 2025 |
|---|---|---|---|---|---|
| 1 | UnitedHealth Group, Inc. | 79,576 | 42.3% | 44 | +6.8% |
| 2 | Gemstone Holdings, Inc. | 36,019 | 19.1% | 36 | -53.5% |
| 3 | Trinity Health Corporation | 22,891 | 12.2% | 24 | +505.1% |
| 4 | PacificSource | 17,066 | 9.1% | 44 | +75.6% |
| 5 | Humana Inc. | 15,212 | 8.1% | 44 | +60.1% |
| 6 | Molina Healthcare, Inc. | 12,845 | 6.8% | 43 | -6.9% |
| 7 | CVS Health Corporation | 1,875 | 1.0% | 44 | +0.2% |
| 8 | Cambia Health Solutions, Inc. | 789 | 0.4% | 44 | -89.3% |
| 9 | Elevance Health, Inc. | 789 | 0.4% | 44 | +3.1% |
| 10 | Fenyx Health Holdings, Inc. | 584 | 0.3% | 44 | — |
| 11 | California Physicians' Service | 320 | 0.2% | 44 | +7.4% |
| 12 | Mitchell Family Office | 250 | 0.1% | 13 | +152.5% |
| 13 | Blue Cross Blue Shield of Michigan Mutual Ins. Co. | 59 | 0.0% | 44 | +1.7% |
| 14 | Highmark Health | 55 | 0.0% | 44 | +1.9% |
| 15 | Health Care Service Corporation | 12 | 0.0% | 44 | -14.3% |
| 16 | Alignment Healthcare USA, LLC | 0 | 0.0% | 44 | — |
| 17 | Allina Health and Aetna Insurance Holding Company | 0 | 0.0% | 44 | — |
| 18 | ATRIO Health Plans | 0 | 0.0% | 2 | — |
| 19 | Aultman Health Foundation | 0 | 0.0% | 44 | — |
| 20 | Aware Integrated, Inc. | 0 | 0.0% | 44 | — |
| 21 | Baystate Health, Inc. | 0 | 0.0% | 44 | — |
| 22 | Bexar County Hospital District | 0 | 0.0% | 1 | — |
| 23 | Blue Cross & Blue Shield of Rhode Island | 0 | 0.0% | 44 | — |
| 24 | Blue Cross and Blue Shield of Massachusetts, Inc. | 0 | 0.0% | 44 | — |
| 25 | Blue Cross Blue Shield of Arizona | 0 | 0.0% | 2 | — |
| 26 | Blue Cross Blue Shield of Kansas | 0 | 0.0% | 44 | — |
| 27 | Blue Cross Blue Shield of Nebraska | 0 | 0.0% | 44 | — |
| 28 | BlueCross BlueShield of Alabama | 0 | 0.0% | 44 | — |
| 29 | BlueCross BlueShield of South Carolina (BCBSSC) | 0 | 0.0% | 44 | — |
| 30 | BlueCross BlueShield of Tennessee | 0 | 0.0% | 44 | — |
| 31 | CAPITAL BLUE CROSS | 0 | 0.0% | 44 | — |
| 32 | CareFirst, Inc. | 0 | 0.0% | 44 | — |
| 33 | CareSource | 0 | 0.0% | 1 | — |
| 34 | Centene Corporation | 0 | 0.0% | 12 | — |
| 35 | Community Health Group | 0 | 0.0% | 1 | — |
| 36 | Corewell Health | 0 | 0.0% | 44 | — |
| 37 | CuraCor Solutions Corp. | 0 | 0.0% | 44 | — |
| 38 | Devoted Health, Inc. | 0 | 0.0% | 5 | — |
| 39 | EmblemHealth, Inc. | 0 | 0.0% | 44 | — |
| 40 | Fallon Community Health Plan, Inc. | 0 | 0.0% | 44 | — |
| 41 | General Catalyst Group Management Holdings LP | 0 | 0.0% | 44 | — |
| 42 | Guidewell Mutual Holding Corporation | 0 | 0.0% | 44 | — |
| 43 | Hawaii Medical Service Association | 0 | 0.0% | 44 | — |
| 44 | Healthfirst, Inc. | 0 | 0.0% | 44 | — |
| 45 | HealthPartners, Inc. | 0 | 0.0% | 44 | — |
| 46 | Henry Ford Health System | 0 | 0.0% | 44 | — |
| 47 | Horizon Mutual Holdings, Inc | 0 | 0.0% | 44 | — |
| 48 | Imperial Health Plan of California | 0 | 0.0% | 2 | — |
| 49 | Independence Health Group, Inc. | 0 | 0.0% | 44 | — |
| 50 | Independent Health Association, Inc. | 0 | 0.0% | 44 | — |
| 51 | Intermountain Health Care, Inc. | 0 | 0.0% | 44 | -100.0% |
| 52 | Kaiser Foundation Health Plan, Inc. | 0 | 0.0% | 20 | — |
| 53 | Lifetime Healthcare, Inc. | 0 | 0.0% | 44 | — |
| 54 | Louisiana Health Service & Indemnity Company | 0 | 0.0% | 44 | — |
| 55 | Martin's Point Health Care, Inc. | 0 | 0.0% | 44 | — |
| 56 | Mass General Brigham Incorporated | 0 | 0.0% | 1 | — |
| 57 | Medica Holding Company | 0 | 0.0% | 44 | — |
| 58 | MEDICAL MUTUAL OF OHIO | 0 | 0.0% | 44 | — |
| 59 | Mercy Care | 0 | 0.0% | 1 | — |
| 60 | Montage Health | 0 | 0.0% | 1 | — |
| 61 | MVP Health Care, Inc. | 0 | 0.0% | 44 | — |
| 62 | NEIGHBORHOOD HEALTH PLAN OF RHODE ISLAND | 0 | 0.0% | 1 | — |
| 63 | Network Health, Inc. | 0 | 0.0% | 44 | — |
| 64 | Presbyterian Healthcare Services | 0 | 0.0% | 1 | — |
| 65 | Providence St Joseph Health | 0 | 0.0% | 3 | — |
| 66 | SANTA CRUZ MONTEREY MERCED SAN BENITO MARIPOSA MAN | 0 | 0.0% | 1 | — |
| 67 | SCAN Group | 0 | 0.0% | 12 | — |
| 68 | Sharp Healthcare | 0 | 0.0% | 4 | — |
| 69 | The Health Plan of West Virginia, Inc. | 0 | 0.0% | 44 | — |
| 70 | The Regents of the University of California | 0 | 0.0% | 1 | — |
| 71 | Universal Health Services, Inc. | 0 | 0.0% | 5 | — |
| 72 | UPMC Health System | 0 | 0.0% | 44 | — |
| 73 | USAble Mutual Insurance Company | 0 | 0.0% | 44 | — |
County view
Leading carrier and Advantage enrollment in each Idaho county. Penetration is from CMS Medicare Monthly Enrollment, 2024.
| County | Advantage enrollees | Leading carrier | Leader share | Carriers | Penetration |
|---|---|---|---|---|---|
| Ada | 59,351 | UnitedHealth Group, Inc. | 39.2% | 61 | 58.2% |
| Canyon | 30,992 | UnitedHealth Group, Inc. | 35.9% | 59 | 63.3% |
| Kootenai | 19,935 | UnitedHealth Group, Inc. | 38.9% | 63 | 44.6% |
| Twin Falls | 10,913 | PacificSource | 30.8% | 59 | 56.0% |
| Bonneville | 8,649 | UnitedHealth Group, Inc. | 61.4% | 55 | 46.1% |
| Bannock | 8,317 | UnitedHealth Group, Inc. | 54.8% | 56 | 51.9% |
| Bonner | 6,104 | UnitedHealth Group, Inc. | 40.3% | 58 | 42.2% |
| Bingham | 3,890 | UnitedHealth Group, Inc. | 55.0% | 52 | 48.9% |
| Payette | 3,607 | Gemstone Holdings, Inc. | 24.3% | 54 | 56.3% |
| Gem | 3,543 | Gemstone Holdings, Inc. | 28.7% | 54 | 62.1% |
| Elmore | 2,489 | UnitedHealth Group, Inc. | 31.0% | 54 | 46.0% |
| Nez Perce | 2,386 | UnitedHealth Group, Inc. | 77.2% | 55 | 37.3% |
| Jerome | 2,258 | PacificSource | 48.6% | 52 | 52.3% |
| Minidoka | 1,901 | UnitedHealth Group, Inc. | 59.6% | 51 | 45.2% |
| Jefferson | 1,896 | UnitedHealth Group, Inc. | 66.6% | 51 | 46.6% |
| Latah | 1,858 | UnitedHealth Group, Inc. | 86.1% | 54 | 29.3% |
| Cassia | 1,761 | UnitedHealth Group, Inc. | 54.4% | 54 | 41.2% |
| Gooding | 1,639 | PacificSource | 48.6% | 55 | 48.1% |
| Washington | 1,629 | Trinity Health Corporation | 33.6% | 54 | 49.9% |
| Owyhee | 1,409 | Trinity Health Corporation | 27.6% | 53 | 57.5% |
| Valley | 1,381 | PacificSource | 50.2% | 54 | 46.3% |
| Shoshone | 1,298 | UnitedHealth Group, Inc. | 72.3% | 52 | 31.2% |
| Boundary | 1,258 | UnitedHealth Group, Inc. | 88.6% | 55 | 41.9% |
| Madison | 1,255 | UnitedHealth Group, Inc. | 59.3% | 52 | 43.4% |
| Boise | 1,252 | Gemstone Holdings, Inc. | 35.9% | 52 | 55.2% |
| Blaine | 1,193 | UnitedHealth Group, Inc. | 91.4% | 56 | 27.5% |
| Idaho | 927 | UnitedHealth Group, Inc. | 91.5% | 52 | 13.2% |
| Franklin | 845 | UnitedHealth Group, Inc. | 74.9% | 50 | 38.5% |
| Fremont | 806 | UnitedHealth Group, Inc. | 54.7% | 54 | 36.1% |
| Adams | 492 | UnitedHealth Group, Inc. | 64.0% | 52 | 40.5% |
| Benewah | 461 | UnitedHealth Group, Inc. | 79.4% | 52 | 7.8% |
| Power | 456 | Gemstone Holdings, Inc. | 45.6% | 51 | 41.0% |
| Clearwater | 423 | UnitedHealth Group, Inc. | 79.7% | 53 | 6.9% |
| Lincoln | 404 | UnitedHealth Group, Inc. | 53.0% | 54 | 43.1% |
| Caribou | 228 | UnitedHealth Group, Inc. | 63.6% | 50 | 13.3% |
| Lemhi | 197 | UnitedHealth Group, Inc. | 100.0% | 52 | 4.0% |
| Oneida | 184 | UnitedHealth Group, Inc. | 73.9% | 51 | 14.6% |
| Teton | 183 | UnitedHealth Group, Inc. | 83.1% | 50 | 5.8% |
| Custer | 174 | UnitedHealth Group, Inc. | 100.0% | 50 | 4.0% |
| Bear Lake | 135 | UnitedHealth Group, Inc. | 70.4% | 51 | 10.9% |
| Lewis | 135 | UnitedHealth Group, Inc. | 81.5% | 50 | 7.2% |
| Camas | 96 | PacificSource | 51.0% | 51 | 34.8% |
| Butte | 19 | Molina Healthcare, Inc. | 100.0% | 50 | 3.9% |
| Clark | 13 | UnitedHealth Group, Inc. | 100.0% | 51 | 47.5% |
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).