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Health insurance in San Mateo County, California

12,908 people here have no coverage and earn in the range a premium tax credit is built for — 49% of everyone uninsured in the county.

Reviewed September 4, 2026 · 2024 Census data

12,908Uninsured, subsidy range 138–400% of poverty
4.4%Uninsured, under 65 26,524 people
3.6%Uninsured, 50 to 64 5,144 people
603,170Under-65 residents 93rd of 3,143

Source: US Census Small Area Health Insurance Estimates, 2024 release. Income bands are measured against the federal poverty level.

How many here a premium tax credit would reach

Of the 26,524 people without coverage in San Mateo County, 12,908 — 49% — earn inside the premium tax credit range. That is near the 51% national median. Within that band itself, 9.2% have no coverage.

Comparatively few people go uncovered

4.4% of San Mateo County's 603,170 under-65 residents have no health coverage — 26,524 people. That is below the California rate of 6.9%, and puts San Mateo County in the bottom quarter of the 3,143 counties measured nationally (3,087th).

Who falls under the Medicaid line

5,960 of San Mateo County's uninsured — 22%, below the 31% typical of counties nationally — earn under $22,025 a year, which in California is Medicaid territory rather than marketplace territory.

The years before Medicare

5,144 people aged 50 to 64 in San Mateo County have no coverage, a rate of 3.6% — close to the 4.4% across all under-65 residents here. Age-rated premiums make this the most expensive group to cover before Medicare.

San Mateo County against California

San Mateo County is the 14th largest of the 34 California counties we publish. Its uninsured rate runs 2.5 points lower than California overall and 4 points fewer of its uninsured sit in the subsidy band than statewide. Coverage among 50 to 64 year olds is better here than across California.

San Mateo CountyCalifornia National median
Uninsured, under 654.4% 6.9%9.8%
Uninsured in the subsidy band12,908 1,173,956—
Subsidy band as a share of uninsured49% 52% 51%
At or below 138% of poverty22% 25% 31%
Uninsured, 50 to 643.6% 6.6% 8.1%

Counties of a similar size

CountyUninsured In the subsidy bandShare
San Francisco County4.0%11,82344%
Ventura County7.0%24,87753%
San Joaquin County7.7%28,59554%
Stanislaus County6.6%17,36156%

What a plan actually costs in San Mateo County

These figures say how many people here a credit would reach. What it would be worth to you depends on your age, household and income — a licensed agent can work that out on the call.

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