The One Big Beautiful Bill Act (OBBBA), enacted on July 4, 2025, will make deep cuts to Medicaid, the Affordable Care Act (ACA) marketplaces, and the Medicare program. Specifically, the law will impose Medicaid work reporting requirements for the expansion population, allow the ACA’s enhanced premium tax credits to expire at the end of this year, and halt reforms to protect low-income Medicare enrollees from high health care costs.
On August 11, the nonpartisan Congressional Budget Office (CBO) projected that the OBBBA’s health care provisions will increase the number of uninsured Americans nationwide by 10 million by 2034. The CBO had previously estimated that 4.2 million people would be uninsured as a result of the expiration of the ACA’s enhanced premium tax credits at the end of this year, which means at least 14.2 million more Americans will be uninsured by 2034. A subsequent KFF analysis translated this 14.2 million figure into state-level coverage losses, finding that the uninsured rate will climb by at least 3 percentage points in 34 states and the District of Columbia.
New congressional district-level estimates from the Center for American Progress build on KFF’s analysis to reveal the law’s harm in even sharper detail. The results show that, under the OBBBA, every state and congressional district in the country will see an increase in the number of uninsured residents by 2034.
The OBBBA will cause millions of Americans to lose their insurance
Losing health coverage has both health and financial consequences. Uninsured individuals are less likely to have no usual source of care, more likely to delay or forgo care due to cost, and more likely to incur medical debt compared to those with health insurance.
The states with the largest projected increases in the number of uninsured residents are California (1.7 million), Florida (1.5 million), Texas (1.4 million), New York (860,000), and Illinois (528,000).
Every member of Congress, regardless of party or geography, will see tens of thousands of their constituents lose coverage under this law. On average, each congressional district will have nearly 33,000 more people uninsured in 2034. The following congressional districts will face the largest increases in uninsured residents:
- Arizona’s 3rd Congressional District: 80,000
- Arizona’s 7th Congressional District: 70,000
- Washington’s 4th Congressional District: 66,000
- Kentucky’s 5th Congressional District: 64,000
- Louisiana’s 6th Congressional District: 64,000
- New York’s 15th Congressional District: 63,000.
These congressional districts have high Medicaid enrollment rates—with more than 30 percent of the population under 65 covered by Medicaid—and they represent diverse regions, from cities to rural areas, underscoring the law’s widespread impact.
Conclusion
The OBBBA will drive up the number of uninsured Americans in every state and every congressional district in the country, reversing more than a decade of progress in expanding coverage. Every lawmaker will see thousands of constituents lose coverage under this law. Families, communities, and health systems nationwide will feel the consequences of these cuts.
See also
The authors would like to thank Andrea Ducas for her contributions to this analysis and Natalie Baker for her fact-checking assistance.
Methodology
To distribute KFF’s state health insurance coverage losses down to congressional districts, the authors created proportional weights for each congressional district’s share of enrollment by coverage type. For Medicaid, the authors weighted coverage losses proportional to each district’s share of state 2024 Medicaid enrollment, per KFF. For the marketplaces, KFF did not have congressional district-level 2024 enrollment data for all states; in those states, ACA coverage losses were distributed in proportion to the state’s total population from the Missouri Census Data Center, consistent with prior KFF analysis. For Medicare, the authors weighted coverage losses proportional to each district’s share of state Medicare enrollment in 2023 using Table 1 of the Centers for Medicare and Medicaid Services’ (CMS) “Medicare Beneficiary Enrollment by Congressional District and State.” For KFF’s coverage loss category titled “Budget Reconciliation Law Medicare and Other Uninsured Increase,” the authors assumed the shares KFF attributed to Medicare, Medicaid, and the ACA nationally were similar in each congressional district. The authors then summed coverage losses across coverage types to obtain a total increase in the number of people uninsured by congressional district.
These estimates do not account for the additional coverage losses expected under the Trump administration’s 2025 Marketplace Integrity and Affordability final rule. The CMS’ analysis of the proposed rule projected that between 750,000 and 2 million fewer people will have marketplace coverage in 2026.