Health insurance is the gateway to preventive care, chronic disease management, and financial protection from medical emergencies. We identified the 25 counties with the lowest uninsured rates in America — places where nearly every resident has some form of health coverage.
The national average uninsured rate is approximately 10.5%. The counties on this list have rates below 4%, with several falling below 2%.
Counties with the Lowest Uninsured Rates
Los Alamos County, NM leads with an uninsured rate of just 2.15%. These counties are concentrated in the Northeast, Upper Midwest, and Hawaii. Massachusetts (13 counties), Rhode Island (3 counties), Minnesota (2 counties), New Mexico (1 counties), Texas (1 counties) lead the rankings.
| Rank | County | State | Uninsured Rate | Health Score | PCP per 100K |
|---|---|---|---|---|---|
| 1 | Los Alamos County | NM | 2.15% | 99.6 | 155.2 |
| 2 | Loving County | TX | 2.22% | 94.1 | N/A |
| 3 | Norfolk County | MA | 2.35% | 98 | 119.7 |
| 4 | Middlesex County | MA | 2.39% | 98.8 | 124.6 |
| 5 | Plymouth County | MA | 2.43% | 92 | 63.4 |
| 6 | Hampshire County | MA | 2.51% | 95.5 | 128.1 |
| 7 | Franklin County | MA | 2.57% | 95.9 | 63.4 |
| 8 | Berkshire County | MA | 2.8% | 87.4 | 109.6 |
| 9 | Barnstable County | MA | 2.98% | 96.1 | 89.9 |
| 10 | Suffolk County | MA | 3.06% | 86.3 | 157.4 |
| 11 | District of Columbia | DC | 3.07% | 86.4 | 128.8 |
| 12 | Worcester County | MA | 3.23% | 90.2 | 93.4 |
| 13 | Carver County | MN | 3.26% | 99.1 | 84.7 |
| 14 | Hampden County | MA | 3.27% | 66.3 | 66.6 |
| 15 | Bristol County | MA | 3.36% | 80.6 | 50.5 |
| 16 | Pennington County | MN | 3.38% | 91.5 | 79.8 |
| 17 | Essex County | MA | 3.48% | 91.7 | 74.1 |
| 18 | Bristol County | RI | 3.55% | 96.3 | 200.7 |
| 19 | Bremer County | IA | 3.63% | 93.1 | 47.8 |
| 20 | Oldham County | KY | 3.65% | 94.3 | 59.7 |
| 21 | Washington County | RI | 3.67% | 97.5 | 81.9 |
| 22 | Placer County | CA | 3.73% | 96 | 122 |
| 23 | Saratoga County | NY | 3.75% | 97.6 | 69.5 |
| 24 | Nantucket County | MA | 3.77% | 99.1 | 41.4 |
| 25 | Newport County | RI | 3.78% | 98.3 | 83.3 |
Why These Counties Have Near-Universal Coverage
Several factors explain the low uninsured rates in these counties:
- Medicaid expansion: Most of these counties are in states that expanded Medicaid under the Affordable Care Act, extending coverage to low-income adults.
- Employer-sponsored insurance: Counties with strong employment bases — particularly in government, healthcare, and education — have high rates of employer-provided coverage.
- Higher incomes: Residents who can afford marketplace plans or direct-purchase insurance are less likely to go uncovered.
- Cultural factors: Some communities have strong norms around healthcare utilization and insurance enrollment that drive higher coverage rates.
Methodology
Uninsured rate data comes from the CDC County Health Rankings (2024) and U.S. Census Bureau American Community Survey (2019-2023 5-Year Estimates). The rate measures the percentage of adults under age 65 without health insurance. Counties with missing data are excluded from the ranking.
Data sources: CDC County Health Rankings & Roadmaps (2024), a Robert Wood Johnson Foundation program, and U.S. Census Bureau American Community Survey (2019-2023). All figures are estimates and may differ from other published analyses due to methodology differences. This content is informational only and does not constitute medical advice.