Health insurance in Yellowstone County, Montana
3 insurers sell 42 marketplace plans here, and 10.4% of under-65 residents have no coverage at all.
Source: CMS Marketplace Open Enrollment Public Use Files and US Census Small Area Health Insurance Estimates, 2026 release.
Who sells here, and how much choice that gives
3 insurers sell marketplace plans in Yellowstone County, offering 42 plans between them, roughly 14 each. It gained 1 since the previous plan year, up from 2.
How many people here have no coverage
10.4% of Yellowstone County's 136,958 under-65 residents have no health coverage — 14,225 people. That is close to the Montana rate of 11.1%, and puts Yellowstone County in the middle half of the 1,817 counties on this site (981st).
How much the marketplace is used
8,221 Yellowstone County residents selected a marketplace plan for 2026: 60 per thousand under-65 residents, 1412th of 1,817. That is under the 78 per thousand typical of published counties. 1,221 of them — 15% — were new rather than renewing.
Yellowstone County against Montana
Yellowstone County is the largest of the 4 Montana counties we publish, by under-65 population. Its uninsured rate runs 0.7 points lower than Montana overall and it carries the same 3 insurers as every other county in the state. Marketplace use is well under the Montana rate.
| Yellowstone County | Montana | Published median | |
|---|---|---|---|
| Uninsured, under 65 | 10.4% | 11.1% | 9.9% |
| Insurers selling | 3 | 3–3 | 4 |
| Plans offered | 42 | — | 57 |
| Selections per 1,000 | 60 | 83 | 78 |
| New rather than renewing | 15% | 14% | 15% |
Counties of a similar size nearby
| County | Under 65 | Uninsured | Insurers | Plans |
|---|---|---|---|---|
| Fairfield County (Ohio) | 137,102 | 6.2% | 7 | 113 |
| Aiken County (South Carolina) | 138,502 | 10.4% | 3 | 43 |
Fairfield County has 7 insurers against this county's 3 — a reminder that the county line, not the state line, is what decides your options.
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