Counties in California by uninsured rate, ages 19 to 34 (US, ACS)

Sierra County had the highest uninsured rate, ages 19 to 34 (US, ACS) of 58 counties in 2021, at 61%. San Francisco County had the lowest, at 5.1%. The median was 11.8% and the figure for California was 11.5%. Source: the U.S. Census Bureau.

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Highest61Sierra County
Median11.858 counties
California11.5History

Map of counties, 2021

Alameda County: 6.8 %Alpine County: 14.8 %Amador County: 6.4 %Butte County: 11.6 %Calaveras County: 8.5 %Colusa County: 15.8 %Contra Costa County: 8.8 %Del Norte County: 7.4 %El Dorado County: 9.1 %Fresno County: 13.2 %Glenn County: 20.7 %Humboldt County: 13.1 %Imperial County: 11.6 %Inyo County: 13.5 %Kern County: 12.4 %Kings County: 13.2 %Lake County: 13.7 %Lassen County: 9.5 %Los Angeles County: 13.7 %Madera County: 14.4 %Marin County: 9.4 %Mariposa County: 12.1 %Mendocino County: 16.1 %Merced County: 13.7 %Modoc County: 19.5 %Mono County: 17.6 %Monterey County: 16.9 %Napa County: 11.4 %Nevada County: 12.2 %Orange County: 11 %Placer County: 6.9 %Plumas County: 6.2 %Riverside County: 13.2 %Sacramento County: 9.4 %San Benito County: 11 %San Bernardino County: 12.6 %San Diego County: 12 %San Francisco County: 5.1 %San Joaquin County: 11.1 %San Luis Obispo County: 9.8 %San Mateo County: 6.5 %Santa Barbara County: 15 %Santa Clara County: 6.2 %Santa Cruz County: 8.1 %Shasta County: 13.7 %Sierra County: 61 %Siskiyou County: 15.1 %Solano County: 9.2 %Sonoma County: 9.6 %Stanislaus County: 9.3 %Sutter County: 10.3 %Tehama County: 11.3 %Trinity County: 30.5 %Tulare County: 12.8 %Tuolumne County: 13.4 %Ventura County: 14.6 %Yolo County: 6.4 %Yuba County: 9.3 %
  • Under 8.3
  • 8.3 to 9.6
  • 9.6 to 12
  • 12 to 13
  • 13 to 15
  • 15 and over
%, 2021. Source: Invokely calculation with data from U.S. Census Bureau. Boundaries: U.S. Census Bureau cartographic boundary files.

All counties, 2021

Sierra County: 61 %Sierra County61Trinity County: 30.5 %Trinity County30.5Glenn County: 20.7 %Glenn County20.7Modoc County: 19.5 %Modoc County19.5Mono County: 17.6 %Mono County17.6Monterey County: 16.9 %Monterey County16.9Mendocino County: 16.1 %Mendocino County16.1Colusa County: 15.8 %Colusa County15.8Siskiyou County: 15.1 %Siskiyou County15.1Santa Barbara County: 15 %Santa Barbara County15Alpine County: 14.8 %Alpine County14.8Ventura County: 14.6 %Ventura County14.6Madera County: 14.4 %Madera County14.4Merced County: 13.7 %Merced County13.7Lake County: 13.7 %Lake County13.7Shasta County: 13.7 %Shasta County13.7Los Angeles County: 13.7 %Los Angeles County13.7Inyo County: 13.5 %Inyo County13.5Tuolumne County: 13.4 %Tuolumne County13.4Kings County: 13.2 %Kings County13.2Riverside County: 13.2 %Riverside County13.2Fresno County: 13.2 %Fresno County13.2Humboldt County: 13.1 %Humboldt County13.1Tulare County: 12.8 %Tulare County12.8San Bernardino County: 12.6 %San Bernardino County12.6Kern County: 12.4 %Kern County12.4Nevada County: 12.2 %Nevada County12.2Mariposa County: 12.1 %Mariposa County12.1San Diego County: 12 %San Diego County12Imperial County: 11.6 %Imperial County11.6Butte County: 11.6 %Butte County11.6Napa County: 11.4 %Napa County11.4Tehama County: 11.3 %Tehama County11.3San Joaquin County: 11.1 %San Joaquin County11.1Orange County: 11 %Orange County11San Benito County: 11 %San Benito County11Sutter County: 10.3 %Sutter County10.3San Luis Obispo County: 9.8 %San Luis Obispo County9.8Sonoma County: 9.6 %Sonoma County9.6Lassen County: 9.5 %Lassen County9.5Sacramento County: 9.4 %Sacramento County9.4Marin County: 9.4 %Marin County9.4Stanislaus County: 9.3 %Stanislaus County9.3Yuba County: 9.3 %Yuba County9.3Solano County: 9.2 %Solano County9.2El Dorado County: 9.1 %El Dorado County9.1Contra Costa County: 8.8 %Contra Costa County8.8Calaveras County: 8.5 %Calaveras County8.5Santa Cruz County: 8.1 %Santa Cruz County8.1Del Norte County: 7.4 %Del Norte County7.4Placer County: 6.9 %Placer County6.9Alameda County: 6.8 %Alameda County6.8San Mateo County: 6.5 %San Mateo County6.5Amador County: 6.4 %Amador County6.4Yolo County: 6.4 %Yolo County6.4Plumas County: 6.2 %Plumas County6.2Santa Clara County: 6.2 %Santa Clara County6.2San Francisco County: 5.1 %San Francisco County5.1Sierra County: 61 %Sierra County61Trinity County: 30.5 %Trinity County30.5Glenn County: 20.7 %Glenn County20.7Modoc County: 19.5 %Modoc County19.5Mono County: 17.6 %Mono County17.6Monterey County: 16.9 %Monterey County16.9Mendocino County: 16.1 %Mendocino County16.1Colusa County: 15.8 %Colusa County15.8Siskiyou County: 15.1 %Siskiyou County15.1Santa Barbara County: 15 %Santa Barbara County15Alpine County: 14.8 %Alpine County14.8Ventura County: 14.6 %Ventura County14.6Madera County: 14.4 %Madera County14.4Merced County: 13.7 %Merced County13.7Lake County: 13.7 %Lake County13.7Shasta County: 13.7 %Shasta County13.7Los Angeles County: 13.7 %Los Angeles County13.7Inyo County: 13.5 %Inyo County13.5Tuolumne County: 13.4 %Tuolumne County13.4Kings County: 13.2 %Kings County13.2Riverside County: 13.2 %Riverside County13.2Fresno County: 13.2 %Fresno County13.2Humboldt County: 13.1 %Humboldt County13.1Tulare County: 12.8 %Tulare County12.8San Bernardino County: 12.6 %San Bernardino County12.6Kern County: 12.4 %Kern County12.4Nevada County: 12.2 %Nevada County12.2Mariposa County: 12.1 %Mariposa County12.1San Diego County: 12 %San Diego County12Imperial County: 11.6 %Imperial County11.6Butte County: 11.6 %Butte County11.6Napa County: 11.4 %Napa County11.4Tehama County: 11.3 %Tehama County11.3San Joaquin County: 11.1 %San Joaquin County11.1Orange County: 11 %Orange County11San Benito County: 11 %San Benito County11Sutter County: 10.3 %Sutter County10.3San Luis Obispo County: 9.8 %San Luis Obispo County9.8Sonoma County: 9.6 %Sonoma County9.6Lassen County: 9.5 %Lassen County9.5Sacramento County: 9.4 %Sacramento County9.4Marin County: 9.4 %Marin County9.4Stanislaus County: 9.3 %Stanislaus County9.3Yuba County: 9.3 %Yuba County9.3Solano County: 9.2 %Solano County9.2El Dorado County: 9.1 %El Dorado County9.1Contra Costa County: 8.8 %Contra Costa County8.8Calaveras County: 8.5 %Calaveras County8.5Santa Cruz County: 8.1 %Santa Cruz County8.1Del Norte County: 7.4 %Del Norte County7.4Placer County: 6.9 %Placer County6.9Alameda County: 6.8 %Alameda County6.8San Mateo County: 6.5 %San Mateo County6.5Amador County: 6.4 %Amador County6.4Yolo County: 6.4 %Yolo County6.4Plumas County: 6.2 %Plumas County6.2Santa Clara County: 6.2 %Santa Clara County6.2San Francisco County: 5.1 %San Francisco County5.1
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

Other periods

About this ranking

People aged 19 to 34 without health insurance coverage of any kind, as a percentage of the civilian noninstitutionalized population aged 19 to 34. United States: American Community Survey five-year estimate, where the period shown is the last year of the five-year span.

Coverage is what people reported at the interview, so the five-year figure averages five years of answers. People whose only coverage is the Indian Health Service count as uninsured. Active-duty military and people living in institutions are outside the universe. For single-year model-based county figures under 65, see uninsured_rate_under_65, uninsured_rate_18_64 and uninsured_rate_under_19 (SAHIE), a different source.

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. American Community Survey 5-year estimates, table B27010: people aged 19 to 34 with no health insurance coverage as a percentage of the civilian noninstitutionalized population aged 19 to 34, calculated with stored inputs. https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b27010.dat. 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). American Community Survey 5-year estimates, table B27010: people aged 19 to 34 with no health insurance coverage as a percentage of the civilian noninstitutionalized population aged 19 to 34, calculated with stored inputs (Counties in California by uninsured rate, ages 19 to 34 (US, ACS), 2021) [Data set]. Retrieved October 12, 2026, from https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b27010.dat

MLA 9

American Community Survey 5-year estimates, table B27010: people aged 19 to 34 with no health insurance coverage as a percentage of the civilian noninstitutionalized population aged 19 to 34, calculated with stored inputs, Counties in California by uninsured rate, ages 19 to 34 (US, ACS), 2021. U.S. Census Bureau, 29 Jan. 2026, https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b27010.dat. Invokely, https://invokely.ai/rankings/uninsured-rate-ages-19-34/california-counties?period=2021. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Census Bureau. 2026. American Community Survey 5-year estimates, table B27010: people aged 19 to 34 with no health insurance coverage as a percentage of the civilian noninstitutionalized population aged 19 to 34, calculated with stored inputs. Counties in California by uninsured rate, ages 19 to 34 (US, ACS), 2021. Dataset. Accessed October 12, 2026. https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b27010.dat. Also distributed by Invokely, https://invokely.ai/rankings/uninsured-rate-ages-19-34/california-counties?period=2021.

Harvard

U.S. Census Bureau (2026) American Community Survey 5-year estimates, table B27010: people aged 19 to 34 with no health insurance coverage as a percentage of the civilian noninstitutionalized population aged 19 to 34, calculated with stored inputs, Counties in California by uninsured rate, ages 19 to 34 (US, ACS), 2021 [Dataset]. Available at: https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b27010.dat, via Invokely: https://invokely.ai/rankings/uninsured-rate-ages-19-34/california-counties?period=2021 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_california_by_2021,
  author = {{U.S. Census Bureau}},
  title = {{American Community Survey 5-year estimates, table B27010: people aged 19 to 34 with no health insurance coverage as a percentage of the civilian noninstitutionalized population aged 19 to 34, calculated with stored inputs: Counties in California by uninsured rate, ages 19 to 34 (US, ACS), 2021}},
  year = {2026},
  howpublished = {Data set},
  url = {https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b27010.dat},
  urldate = {2026-10-12},
  note = {Accessed via Invokely, https://invokely.ai/rankings/uninsured-rate-ages-19-34/california-counties?period=2021. Publisher attribution: U.S. Census Bureau. American Community Survey 5-year estimates, table B27010: people aged 19 to 34 with no health insurance coverage as a percentage of the civilian noninstitutionalized population aged 19 to 34, calculated with stored inputs. https://www2.census.gov/programs-surveys/acs/summary\_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b27010.dat. Retrieved 2026-10-12.},
}
RIS
TY  - DATA
AU  - U.S. Census Bureau
TI  - American Community Survey 5-year estimates, table B27010: people aged 19 to 34 with no health insurance coverage as a percentage of the civilian noninstitutionalized population aged 19 to 34, calculated with stored inputs: Counties in California by uninsured rate, ages 19 to 34 (US, ACS), 2021
PY  - 2026
DA  - 2026/01/29
PB  - U.S. Census Bureau
DB  - Invokely
UR  - https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b27010.dat
L2  - https://invokely.ai/rankings/uninsured-rate-ages-19-34/california-counties?period=2021
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/uninsured-rate-ages-19-34/california-counties?period=2021.
N1  - Publisher attribution: U.S. Census Bureau. American Community Survey 5-year estimates, table B27010: people aged 19 to 34 with no health insurance coverage as a percentage of the civilian noninstitutionalized population aged 19 to 34, calculated with stored inputs. https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b27010.dat. Retrieved 2026-10-12.
ER  - 
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Rank Counties in California by uninsured rate, ages 19 to 34 (US, ACS) using official data, and cite the source.
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Questions

Which county has the highest uninsured rate, ages 19 to 34 (US, ACS)?

Sierra County, with 61% in 2021, according to the U.S. Census Bureau.

Which county has the lowest uninsured rate, ages 19 to 34 (US, ACS)?

San Francisco County, with 5.1% in 2021.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, American Community Survey 5-year estimates, table B27010: people aged 19 to 34 with no health insurance coverage as a percentage of the civilian noninstitutionalized population aged 19 to 34, calculated with stored inputs. Retrieved 2026-10-12.

Uninsured rate, ages 19 to 34 (US, ACS): other rankings

Counties in California: more rankings