A new analysis from the Congressional Budget Office (CBO) projects that if H.R. 1, the “One Big Beautiful Bill Act,” becomes law, the number of Americans without health insurance will rise by 10.9 million by 2034. 

The proposed cuts to Medicaid and Affordable Care Act (ACA) programs will affect low-income families and individuals currently receiving federal health coverage the most. H.R. 1 introduces more frequent eligibility checks, work requirements, and reduced federal funding for Medicaid, making it harder for many to qualify or maintain coverage.

Federal spending on Medicaid will decrease by an estimated $806 billion over ten years. The bill also cuts federal spending on financial assistance for ACA Marketplace plans by $301 billion over ten years.

States that expanded Medicaid under the ACA will see reduced federal support, which could force some states to scale back coverage or tighten eligibility, further increasing the uninsured rate among vulnerable populations.

The CBO estimates that gross benchmark premiums in ACA marketplace plans will decline by 12.2% by 2034. However, this reduction reflects changes before accounting for premium tax credits, and many low-income consumers will lose subsidies or coverage altogether, offsetting the benefit of lower premiums for those most at risk.

The bill also specifically bars federal funding for Medicaid and ACA subsidies for individuals without verified citizenship or satisfactory immigration status. As a result, 1.4 million non-citizens currently covered by state-only funded programs would lose their health insurance.

Many lawfully present immigrants (e.g., refugees, asylees, TPS holders) would lose access to Medicaid and ACA subsidies. The bill eliminates special rules allowing subsidies for those ineligible for Medicaid due to immigration status.