If the amount they pay in premiums doubled, about one in four enrollees in ACA Marketplace health plans say they would “very likely” go without insurance in 2026, finds a KFF survey of Marketplace enrollees fielded shortly after open enrollment began in the first weeks of November 2025. One in three say they would be “very likely” to look for a lower-premium Marketplace plan.

The ACA enhanced premium tax credit has driven growth in Marketplace enrollment and offset declines in Medicaid coverage, holding 2024’s 8% uninsured rate at its near-historic low, according to new Census Bureau data.

This analysis apportions the increase in the number of uninsured across the 50 states and DC. CBO estimates that the reconciliation law will increase the number of uninsured by 10M in 2034 and rise to over 14M if enhanced premium tax credits for ACA Marketplace enrollees expire later this year.

This Health Policy 101 chapter examines the share of the United States population who are uninsured, highlighting their demographics and the challenges they face because of the lack of coverage.

This analysis estimates that 1.4 million uninsured individuals in the 10 states without Medicaid expansion, including many working adults, people of color, and those with disabilities, remain in the “coverage gap,” ineligible for Medicaid or for tax credits that would make coverage ACA's Marketplaces affordable to them.

The number of people ages 0-64 who were uninsured held steady at 25.3 million in 2023, although the number of uninsured children rose from 3.8 million to 4.0 million. Most uninsured people are in low-income families and have at least one worker in the family.

Over half who were disenrolled say they put off needed medical care while trying to renew Medicaid. Overall, 19% of adults who had Medicaid prior to the start of unwinding say they were disenrolled at some point in the past year. Of this group, a large majority (70%) were left at least temporarily uninsured.