As of 2025, 40 states plus the District of Columbia have expanded Medicaid under the Affordable Care Act. That covers the vast majority of the country, leaving just 10 states that have not adopted expansion. The expansion extends Medicaid eligibility to adults earning up to 138% of the federal poverty level, roughly $20,800 per year for a single person. As of mid-2024, nearly 21 million adults were enrolled through the expansion nationwide.
Full List of States That Expanded Medicaid
The following 40 states and Washington, D.C. have adopted and implemented Medicaid expansion:
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- District of Columbia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Dakota
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
Not all of these states expanded at the same time. Some, like California and New York, adopted expansion in 2014 when the ACA first made it available. Others came much later. North Carolina was one of the most recent, implementing expansion on December 1, 2023. South Dakota expanded around the same period after voters approved it through a ballot initiative in 2022.
States That Have Not Expanded
Ten states have not adopted Medicaid expansion. These are mostly in the South and include Texas, Florida, Georgia, Mississippi, Alabama, Tennessee, South Carolina, Wisconsin, Wyoming, and Kansas. In these states, many low-income adults without children have no pathway to Medicaid coverage, and those who earn too little to qualify for marketplace subsidies fall into what’s known as the “coverage gap.”
Several of these states have seen legislative pushes or ballot initiative campaigns over the years, but none have crossed the finish line. Wisconsin is a unique case: it covers adults up to 100% of the federal poverty level through a state waiver but has not formally adopted the ACA expansion, meaning it doesn’t receive the higher federal matching rate that expansion states get.
Who Qualifies Under Expansion
The ACA extended Medicaid eligibility to all adults under 65 with household incomes below 133% of the federal poverty level. A built-in income disregard of 5 percentage points effectively raises that threshold to 138% FPL. For a single adult in 2024, that’s roughly $20,800 per year. For a family of four, it’s about $43,000.
Before expansion, Medicaid in most states covered only specific groups: pregnant women, children, people with disabilities, and very low-income parents. Childless adults were largely excluded no matter how little they earned. Expansion eliminated that categorical requirement, making income the primary test for eligibility.
How the Federal Government Pays for It
One reason expansion has been attractive to states is the federal funding structure. For the first three years (2014 through 2016), the federal government covered 100% of costs for the newly eligible population. That rate gradually stepped down to 95% in 2017, 94% in 2018, 93% in 2019, and settled at 90% from 2020 onward. That 90% match is significantly higher than the standard Medicaid match rate, which varies by state but averages around 60%.
To sweeten the deal for holdout states, the American Rescue Plan Act of 2021 offered an additional incentive: states that newly expanded would receive a 5 percentage point increase in their federal matching rate for all existing Medicaid programs during their first two years of expansion. For large states, that bonus could be worth hundreds of millions of dollars annually, often exceeding the state’s share of the expansion cost itself.
Impact on Health and Hospitals
Expansion has had measurable effects on population health. Research from the Keck School of Medicine at USC found that broadening Medicaid access was associated with approximately a 3.8% reduction in adult deaths per year across expansion states. That translates to roughly 12 fewer deaths per 100,000 adults annually compared to states that didn’t expand.
Rural hospitals have been particularly affected by expansion decisions. In non-expansion states, hospitals absorb large amounts of uncompensated care from uninsured patients, which strains their finances. Studies have found that expansion improved hospital financial performance and lowered the likelihood of closure, especially in rural areas that previously had high uninsured rates. Critical access hospitals, the small facilities that serve as the only source of care in many rural communities, have been especially vulnerable to closure in states that didn’t expand because of the bad debt they accumulate providing charity care.
Work Requirements on the Horizon
The political landscape around expansion continues to shift. New Medicaid work requirements are set to apply to expansion adults, meaning people who gained coverage through the expansion may need to document work or work-related activities to maintain their eligibility. Georgia and Wisconsin, which cover some adults through partial waiver expansions rather than full ACA expansion, will also be affected. How these requirements are implemented, and how many people lose coverage as a result, will shape the practical value of expansion going forward.