A significant legislative proposal from the U.S. House of Representatives, titled the "One Big Beautiful Bill Act," is projected to cause millions of Americans to lose their health insurance coverage under Medicaid and the Affordable Care Act (ACA). The bill, which aims to fund priorities such as nearly $4 trillion in tax cuts by reducing spending on these health programs, is now under consideration by the Senate. According to the nonpartisan Congressional Budget Office (CBO), approximately 11 million people could lose health coverage due to specific provisions in the House bill if it becomes law. An additional 4 million are estimated to lose insurance as Obamacare subsidies, which the bill does not extend, expire. The anticipated rise in uninsured individuals would stem from new barriers to access, increased insurance costs, and the outright denial of benefits for certain groups, including some legal immigrants.

The proposed legislation would add an estimated $2.4 trillion to the national debt over a decade, even after factoring in over $900 billion in cuts to health care programs during the same period, as estimated by the Penn Wharton Budget Model. Health policy experts like Alice Burns, associate director with KFF's program on Medicaid and the uninsured, characterize these proposed changes as potentially the largest retraction in health insurance availability in U.S. history, making the reactions of individuals, providers, and states difficult to predict. Healthcare cuts have historically been contentious, and some Republican senators have expressed reservations about measures like Medicaid cuts, potentially impacting the bill's passage through the Senate.

Impact on Medicaid Coverage

Federal funding cuts to Medicaid are expected to have widespread consequences. Allison Orris, senior fellow and director of Medicaid policy at the Center on Budget and Policy Priorities, stated that "no population, frankly, is safe" from a bill proposing over $800 billion in Medicaid cuts over ten years, as states would be forced to make adjustments. A primary driver of Medicaid coverage loss would be new work requirements for individuals aged 19 to 64 in states that expanded Medicaid under the ACA, mandating at least 80 hours of work or qualifying activities per month. States would also face new burdens in verifying compliance and conducting redeterminations more frequently.

House Speaker Mike Johnson has argued that "4.8 million people will not lose their Medicaid coverage unless they choose to do so," asserting the work requirements are not overly cumbersome. However, the CBO estimates these requirements would lead to 5.2 million adults losing federal Medicaid coverage, resulting in 4.8 million becoming uninsured. KFF's Alice Burns suggests these estimates might be conservative, projecting that 10.3 million could lose Medicaid, with 7.8 million becoming uninsured, due to individuals failing to report work hours correctly or submit exemption paperwork. Furthermore, the bill proposes to restrict states' use of health care provider taxes for Medicaid funding, potentially forcing states to cut coverage or other essential services. The legislation also includes delaying Biden-era rules designed to simplify Medicaid enrollment and renewal, particularly for older adults and individuals with disabilities, until 2035, and reducing federal matching rates for states that cover undocumented immigrants.

Changes to the Affordable Care Act (ACA)

The Affordable Care Act marketplaces, currently providing coverage to over 24 million people, are a vital source of insurance for those without employer-sponsored plans, including the self-employed, low-wage workers, and older individuals not yet eligible for Medicare. Drew Altman, president and CEO of KFF, noted that the House legislation would "dramatically" reduce ACA enrollment through a combination of several technical yet consequential changes.

A major factor contributing to potential coverage loss is the non-extension of enhanced ACA subsidies. These premium tax credits, which significantly lowered monthly premiums and expanded eligibility, are set to expire after the current year. The CBO projects that 4.2 million people will become uninsured by 2034 if these subsidies are not continued. For those who maintain coverage, costs are expected to rise substantially; for instance, a typical family of four with an income of $65,000 could face an additional $2,400 in annual premium costs, according to CBPP estimates. John Graves, a professor at Vanderbilt University School of Medicine, commented that individuals might forego coverage if they "simply can't afford to insure themselves."

The bill also introduces several administrative hurdles expected to reduce ACA enrollment by over 3 million people, according to CBO projections. These include shortening the annual open enrollment period to December 15 (from January 15 in most states), eliminating automatic re-enrollment which was utilized by over half of renewing consumers in 2025, and requiring households to verify eligibility details like income and immigration status before receiving subsidies. Kent Smetters from the University of Pennsylvania's Wharton School highlighted these broad adjustments to eligibility. John Graves likened these administrative complexities to making a road bumpier, inevitably causing more "apples to fall off the cart."

Another significant change involves eliminating repayment caps for premium subsidies. Currently, many households have a limit on how much excess subsidy they must repay if their actual income exceeds their estimate. The House bill would require full repayment from all recipients, regardless of income. KFF's Altman described this as potentially "cruel" in practice, given the income volatility often experienced by low-income individuals in hourly wage jobs or small businesses, making accurate income prediction nearly impossible.

Finally, the legislation seeks to curtail ACA access for certain immigrant groups. Starting January 1, 2027, many lawfully present immigrants, such as refugees, asylees, and those with Temporary Protected Status, would become ineligible for subsidized insurance on ACA exchanges. Additionally, Deferred Action for Childhood Arrivals (DACA) recipients, currently considered "lawfully present" for health coverage purposes in many states, would be barred from purchasing insurance through ACA exchanges nationwide.