Health insurance in Williamson County, Tennessee
5 insurers sell 65 marketplace plans here, and 6.5% 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
5 insurers compete in Williamson County with 65 plans between them, about 13 plans each. It gained 2 since the previous plan year, up from 3.
Coverage is better here than across the state
6.5% of Williamson County's 230,574 under-65 residents have no health coverage — 14,875 people. That is far below Tennessee as a whole, which sits at 11.3% — 4.8 points better than its own state, and puts Williamson County in the bottom quarter of the 1,817 counties on this site (1630th).
Some of those 14,875 are in the Tennessee coverage gap: under $15,960 a year, too little for a subsidy and no expanded Medicaid to fall back on.
How much the marketplace is used
16,038 Williamson County residents selected a marketplace plan for 2026: 70 per thousand under-65 residents, 1261st of 1,817. That is close to the 78 per thousand typical of published counties. 2,937 of them — 18% — were new rather than renewing.
Williamson County against Tennessee
Williamson County is the 6th largest of the 11 Tennessee counties we publish. Its uninsured rate runs 4.8 points lower than Tennessee overall and with 5 insurers it is as well served as anywhere in Tennessee. Marketplace use is well under the Tennessee rate.
| Williamson County | Tennessee | Published median | |
|---|---|---|---|
| Uninsured, under 65 | 6.5% | 11.3% | 9.9% |
| Insurers selling | 5 | 3–5 | 4 |
| Plans offered | 65 | — | 57 |
| Selections per 1,000 | 70 | 98 | 78 |
| New rather than renewing | 18% | 16% | 15% |
Counties of a similar size nearby
| County | Under 65 | Uninsured | Insurers | Plans |
|---|---|---|---|---|
| Montgomery County | 216,157 | 8.6% | 5 | 65 |
| Hamilton County | 306,635 | 11.5% | 5 | 59 |
| Wilson County | 142,559 | 8.8% | 5 | 65 |
Every one of them has the same number of insurers, so this is a consistent regional market.
Other Tennessee counties · Where the subsidy stops · Enrollment dates