Data / Rankings / Uninsured rate, ages 18 to 64 (US model-based estimate) / Counties in California

Counties in California by uninsured rate, ages 18 to 64 (US model-based estimate)

Monterey County had the highest uninsured rate, ages 18 to 64 (US model-based estimate) of 58 counties in 2023, at 14.2%. San Francisco County had the lowest, at 4.6%. The median was 8% and the figure for California was 9%. Source: the U.S. Census Bureau.

Highest14.2Monterey County
Lowest4.6San Francisco County
Median858 counties
California9History

All counties, 2023

Monterey County: 14.2 %Monterey County14.2Madera County: 13.9 %Madera County13.9Tulare County: 12.7 %Tulare County12.7Santa Barbara County: 12.5 %Santa Barbara County12.5Merced County: 12.3 %Merced County12.3Kern County: 11.9 %Kern County11.9Glenn County: 11.4 %Glenn County11.4Mono County: 11.4 %Mono County11.4Imperial County: 11.2 %Imperial County11.2Kings County: 11 %Kings County11Colusa County: 10.9 %Colusa County10.9San Bernardino County: 10.9 %San Bernardino County10.9Riverside County: 10.7 %Riverside County10.7Sutter County: 10.7 %Sutter County10.7Fresno County: 10.6 %Fresno County10.6Los Angeles County: 10.6 %Los Angeles County10.6Ventura County: 10.2 %Ventura County10.2Lake County: 10.1 %Lake County10.1Mendocino County: 10.1 %Mendocino County10.1Del Norte County: 9.4 %Del Norte County9.4San Joaquin County: 8.9 %San Joaquin County8.9Yuba County: 8.8 %Yuba County8.8Stanislaus County: 8.7 %Stanislaus County8.7Modoc County: 8.6 %Modoc County8.6Shasta County: 8.6 %Shasta County8.6Tehama County: 8.6 %Tehama County8.6Humboldt County: 8.4 %Humboldt County8.4Orange County: 8.3 %Orange County8.3San Benito County: 8 %San Benito County8San Diego County: 8 %San Diego County8Siskiyou County: 8 %Siskiyou County8Butte County: 7.9 %Butte County7.9Lassen County: 7.9 %Lassen County7.9Napa County: 7.8 %Napa County7.8Santa Cruz County: 7.8 %Santa Cruz County7.8Sonoma County: 7.7 %Sonoma County7.7Mariposa County: 7.4 %Mariposa County7.4San Luis Obispo County: 7.4 %San Luis Obispo County7.4Yolo County: 7.4 %Yolo County7.4Sacramento County: 7.3 %Sacramento County7.3Inyo County: 7.2 %Inyo County7.2Amador County: 7.1 %Amador County7.1Trinity County: 7.1 %Trinity County7.1Tuolumne County: 7.1 %Tuolumne County7.1Contra Costa County: 7 %Contra Costa County7Sierra County: 6.8 %Sierra County6.8Calaveras County: 6.6 %Calaveras County6.6Solano County: 6.5 %Solano County6.5Nevada County: 6.4 %Nevada County6.4Plumas County: 6.2 %Plumas County6.2Alpine County: 6.1 %Alpine County6.1San Mateo County: 5.7 %San Mateo County5.7Alameda County: 5.6 %Alameda County5.6Santa Clara County: 5.5 %Santa Clara County5.5El Dorado County: 5.4 %El Dorado County5.4Marin County: 5.2 %Marin County5.2Placer County: 5 %Placer County5San Francisco County: 4.6 %San Francisco County4.6
%. Source: U.S. Census Bureau, Small Area Health Insurance Estimates (SAHIE): percent uninsured, ages 18 to 64, all races, both sexes, all income levels, states and counties. Retrieved 2026-10-12.

Full ranking

RankCounties2023 (%)Change on 2022
1Monterey County14.2-0.7 pts
2Madera County13.9+1.3 pts
3Tulare County12.7+0.4 pts
4Santa Barbara County12.5+1.1 pts
5Merced County12.3+1.1 pts
6Kern County11.9+1.9 pts
7Glenn County11.4+0.1 pts
7Mono County11.4-0.3 pts
9Imperial County11.2-0.1 pts
10Kings County11+1.7 pts
11Colusa County10.9-1.4 pts
11San Bernardino County10.90 pts
13Riverside County10.7+0.4 pts
13Sutter County10.7-0.1 pts
15Fresno County10.6+0.7 pts
15Los Angeles County10.6-0.7 pts
17Ventura County10.2-0.2 pts
18Lake County10.1+1 pts
18Mendocino County10.1-2.7 pts
20Del Norte County9.4-0.6 pts
21San Joaquin County8.9-0.8 pts
22Yuba County8.8+0.4 pts
23Stanislaus County8.7-0.2 pts
24Modoc County8.6-1 pts
24Shasta County8.6-0.4 pts
24Tehama County8.6-0.5 pts
27Humboldt County8.4+0.2 pts
28Orange County8.3-0.5 pts
29San Benito County8-0.3 pts
29San Diego County8-0.4 pts
29Siskiyou County8-2 pts
32Butte County7.9-1.2 pts
32Lassen County7.9+0.7 pts
34Napa County7.8-0.5 pts
34Santa Cruz County7.8+0.2 pts
36Sonoma County7.7-0.1 pts
37Mariposa County7.4-0.5 pts
37San Luis Obispo County7.4-0.9 pts
37Yolo County7.4+0.8 pts
40Sacramento County7.3+0.9 pts
41Inyo County7.2-1.8 pts
42Amador County7.1+0.3 pts
42Trinity County7.1-0.1 pts
42Tuolumne County7.1+0.4 pts
45Contra Costa County7+0.7 pts
46Sierra County6.8-0.7 pts
47Calaveras County6.6-1.4 pts
48Solano County6.5-0.2 pts
49Nevada County6.4-0.9 pts
50Plumas County6.2-0.9 pts
51Alpine County6.1-1.2 pts
52San Mateo County5.7+0.4 pts
53Alameda County5.6+0.4 pts
54Santa Clara County5.5+0.7 pts
55El Dorado County5.4-0.7 pts
56Marin County5.2-0.9 pts
57Placer County5+0.6 pts
58San Francisco County4.60 pts

Other periods

About this ranking

People aged 18 to 64 without health insurance coverage of any kind, as a percentage of all people aged 18 to 64. United States: Census Bureau Small Area Health Insurance Estimates (SAHIE) for states and counties, all races, both sexes and all income levels.

A model-based single-year estimate that combines the American Community Survey with administrative records and population estimates, so every county gets a figure. Covers states and counties only, because the SAHIE dataset files have no national row. The Census Bureau advises comparing years from 2008 on only; 2013 is the updated release. Working-age adults; the rate for everyone under 65 is uninsured_rate_under_65.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.

How to cite

U.S. Census Bureau. Small Area Health Insurance Estimates (SAHIE): percent uninsured, ages 18 to 64, all races, both sexes, all income levels, states and counties. https://www2.census.gov/programs-surveys/sahie/datasets/time-series/estimates-acs/sahie-2023-csv.zip. Retrieved 2026-10-12.

Citation styles

The publisher is the author. Invokely is named only as the place the figures were read, where a style asks for it.

APA 7

U.S. Census Bureau. (2026). Small Area Health Insurance Estimates (SAHIE): percent uninsured, ages 18 to 64, all races, both sexes, all income levels, states and counties (Counties in California by uninsured rate, ages 18 to 64 (US model-based estimate), 2023) [Data set]. Retrieved October 12, 2026, from https://www2.census.gov/programs-surveys/sahie/datasets/time-series/estimates-acs/sahie-2023-csv.zip

MLA 9

Small Area Health Insurance Estimates (SAHIE): percent uninsured, ages 18 to 64, all races, both sexes, all income levels, states and counties, Counties in California by uninsured rate, ages 18 to 64 (US model-based estimate), 2023. U.S. Census Bureau, 6 Aug. 2026, https://www2.census.gov/programs-surveys/sahie/datasets/time-series/estimates-acs/sahie-2023-csv.zip. Invokely, https://invokely.ai/rankings/uninsured-rate-ages-18-64/california-counties?period=2023. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Census Bureau. 2026. Small Area Health Insurance Estimates (SAHIE): percent uninsured, ages 18 to 64, all races, both sexes, all income levels, states and counties. Counties in California by uninsured rate, ages 18 to 64 (US model-based estimate), 2023. Dataset. Accessed October 12, 2026. https://www2.census.gov/programs-surveys/sahie/datasets/time-series/estimates-acs/sahie-2023-csv.zip. Also distributed by Invokely, https://invokely.ai/rankings/uninsured-rate-ages-18-64/california-counties?period=2023.

Harvard

U.S. Census Bureau (2026) Small Area Health Insurance Estimates (SAHIE): percent uninsured, ages 18 to 64, all races, both sexes, all income levels, states and counties, Counties in California by uninsured rate, ages 18 to 64 (US model-based estimate), 2023 [Dataset]. Available at: https://www2.census.gov/programs-surveys/sahie/datasets/time-series/estimates-acs/sahie-2023-csv.zip, via Invokely: https://invokely.ai/rankings/uninsured-rate-ages-18-64/california-counties?period=2023 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_california_by_2023,
  author = {{U.S. Census Bureau}},
  title = {{Small Area Health Insurance Estimates (SAHIE): percent uninsured, ages 18 to 64, all races, both sexes, all income levels, states and counties: Counties in California by uninsured rate, ages 18 to 64 (US model-based estimate), 2023}},
  year = {2026},
  howpublished = {Data set},
  url = {https://www2.census.gov/programs-surveys/sahie/datasets/time-series/estimates-acs/sahie-2023-csv.zip},
  urldate = {2026-10-12},
  note = {Accessed via Invokely, https://invokely.ai/rankings/uninsured-rate-ages-18-64/california-counties?period=2023. Publisher attribution: U.S. Census Bureau. Small Area Health Insurance Estimates (SAHIE): percent uninsured, ages 18 to 64, all races, both sexes, all income levels, states and counties. https://www2.census.gov/programs-surveys/sahie/datasets/time-series/estimates-acs/sahie-2023-csv.zip. Retrieved 2026-10-12.},
}
RIS
TY  - DATA
AU  - U.S. Census Bureau
TI  - Small Area Health Insurance Estimates (SAHIE): percent uninsured, ages 18 to 64, all races, both sexes, all income levels, states and counties: Counties in California by uninsured rate, ages 18 to 64 (US model-based estimate), 2023
PY  - 2026
DA  - 2026/08/06
PB  - U.S. Census Bureau
DB  - Invokely
UR  - https://www2.census.gov/programs-surveys/sahie/datasets/time-series/estimates-acs/sahie-2023-csv.zip
L2  - https://invokely.ai/rankings/uninsured-rate-ages-18-64/california-counties?period=2023
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/uninsured-rate-ages-18-64/california-counties?period=2023.
N1  - Publisher attribution: U.S. Census Bureau. Small Area Health Insurance Estimates (SAHIE): percent uninsured, ages 18 to 64, all races, both sexes, all income levels, states and counties. https://www2.census.gov/programs-surveys/sahie/datasets/time-series/estimates-acs/sahie-2023-csv.zip. Retrieved 2026-10-12.
ER  -
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Questions

Which county has the highest uninsured rate, ages 18 to 64 (US model-based estimate)?

Monterey County, with 14.2% in 2023, according to the U.S. Census Bureau.

Which county has the lowest uninsured rate, ages 18 to 64 (US model-based estimate)?

San Francisco County, with 4.6% in 2023.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, Small Area Health Insurance Estimates (SAHIE): percent uninsured, ages 18 to 64, all races, both sexes, all income levels, states and counties. Retrieved 2026-10-12.

Uninsured rate, ages 18 to 64 (US model-based estimate): other rankings

Counties in California: more rankings