Counties in California by uninsured rate, ages 35 to 64 (US, ACS)
Mono County had the highest uninsured rate, ages 35 to 64 (US, ACS) of 58 counties in 2021, at 15.4%. Placer County had the lowest, at 3.9%. The median was 8.8% and the figure for California was 9.4%. Source: the U.S. Census Bureau.
Map of counties, 2021
- Under 6.2
- 6.2 to 8
- 8 to 8.8
- 8.8 to 9.8
- 9.8 to 12
- 12 and over
All counties, 2021
Full ranking
Other periods
About this ranking
People aged 35 to 64 without health insurance coverage of any kind, as a percentage of the civilian noninstitutionalized population aged 35 to 64. 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 35 to 64 with no health insurance coverage as a percentage of the civilian noninstitutionalized population aged 35 to 64, 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
APA 7
U.S. Census Bureau. (2026). American Community Survey 5-year estimates, table B27010: people aged 35 to 64 with no health insurance coverage as a percentage of the civilian noninstitutionalized population aged 35 to 64, calculated with stored inputs (Counties in California by uninsured rate, ages 35 to 64 (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 35 to 64 with no health insurance coverage as a percentage of the civilian noninstitutionalized population aged 35 to 64, calculated with stored inputs, Counties in California by uninsured rate, ages 35 to 64 (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-35-64/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 35 to 64 with no health insurance coverage as a percentage of the civilian noninstitutionalized population aged 35 to 64, calculated with stored inputs. Counties in California by uninsured rate, ages 35 to 64 (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-35-64/california-counties?period=2021.
Harvard
U.S. Census Bureau (2026) American Community Survey 5-year estimates, table B27010: people aged 35 to 64 with no health insurance coverage as a percentage of the civilian noninstitutionalized population aged 35 to 64, calculated with stored inputs, Counties in California by uninsured rate, ages 35 to 64 (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-35-64/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 35 to 64 with no health insurance coverage as a percentage of the civilian noninstitutionalized population aged 35 to 64, calculated with stored inputs: Counties in California by uninsured rate, ages 35 to 64 (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-35-64/california-counties?period=2021. Publisher attribution: U.S. Census Bureau. American Community Survey 5-year estimates, table B27010: people aged 35 to 64 with no health insurance coverage as a percentage of the civilian noninstitutionalized population aged 35 to 64, 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 35 to 64 with no health insurance coverage as a percentage of the civilian noninstitutionalized population aged 35 to 64, calculated with stored inputs: Counties in California by uninsured rate, ages 35 to 64 (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-35-64/california-counties?period=2021
Y2 - 2026/10/12
N1 - Accessed via Invokely, https://invokely.ai/rankings/uninsured-rate-ages-35-64/california-counties?period=2021.
N1 - Publisher attribution: U.S. Census Bureau. American Community Survey 5-year estimates, table B27010: people aged 35 to 64 with no health insurance coverage as a percentage of the civilian noninstitutionalized population aged 35 to 64, 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 -
Use this data in your AI agent
Invokely serves this figure to AI assistants through MCP and to code through a REST API, with the source and citation attached. Ask your assistant:
Rank Counties in California by uninsured rate, ages 35 to 64 (US, ACS) using official data, and cite the source.
rank_places {"indicator":"uninsured_rate_35_64","level":"province","within":"California","limit":10}
GET https://invokely.ai/api/v1/rank?indicator=uninsured_rate_35_64&level=province&within=California&limit=10Questions
Which county has the highest uninsured rate, ages 35 to 64 (US, ACS)?
Mono County, with 15.4% in 2021, according to the U.S. Census Bureau.
Which county has the lowest uninsured rate, ages 35 to 64 (US, ACS)?
Placer County, with 3.9% 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 35 to 64 with no health insurance coverage as a percentage of the civilian noninstitutionalized population aged 35 to 64, calculated with stored inputs. Retrieved 2026-10-12.
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