How many uninsured are in between programs and how many of them would be eligible if all states adopted Medicaid expansion?
Ten years after the Affordable Care Act (ACA) went into effect, ten states have not adopted Medicaid expansion, leaving 1.5 million uninsured people without an affordable coverage option. The repeal of Medicaid's continuous enrollment provision, as well as the ongoing financial difficulties of rural hospitals, has drawn attention to gaps in Medicaid coverage in states that did not adopt the expansion, and the availability of temporary expanded federal funding for states that recently adopted the expansion has reignited discussions about expanding the program in some of these states.
Two states (South Dakota and North Carolina) expanded the Medicaid program in 2023, reducing the number of uninsured low-income individuals without access to Medicaid. The program expansion in these two states brought the number of states that adopted the expansion to 40, leaving the District of Columbia with ten states. Using data for 2022, the most recent year available, this brief provides estimates of the number and characteristics of uninsured individuals in the ten states that did not adopt expansion who would have been covered by Medicaid if their states had adopted Medicaid expansion. An overview of the methodology underlying the analysis is provided in the Data and Methods section, and more detailed information is provided in the Technical Appendices.
What is a gap in coverage?
A coverage gap exists in states that have not adopted the ACA Medicaid program expansion for adults not eligible for Medicaid coverage or Marketplace subsidies. The ACA expanded the Medicaid program to non-elderly adults with incomes up to 138% FPL ($20,782 per year per person in 2024) with increased federal funds (currently 90%). The Medicaid expansion established a uniform statewide eligibility threshold for low-income parents and introduced new Medicaid coverage for adults without dependent children. However, a 2012 Supreme Court ruling effectively made the program expansion optional for states. As of February 2024, 40 states and the District of Columbia have expanded Medicaid (Figure 1).
In the remaining ten states that have not adopted Medicaid expansion, an estimated 1.5 million people fall into the coverage gap. Adults who fall into this gap have incomes above their state's Medicaid eligibility but below the poverty level, making them ineligible for subsidies under the ACA Marketplaces program (Figure 2). When the ACA was passed, it was not intended that states would be allowed to opt out of the Medicaid expansion; therefore, subsidies in Marketplaces are not available to people with incomes below the poverty level.
Medicaid eligibility for adults in states that have not expanded their programs is very low. In these states, the median income limit for parents is only 38% FPL, or the annual income of a family of three in 2024 would be $9,812, and in almost all states that have not expanded the program (except Wisconsin, which received a waiver), childless adults are ineligible regardless of their income (Figure 3). In Texas, the state with the lowest eligibility threshold, parents in a family of three with incomes above $4,131 per year, or just $344 per month, are ineligible for Medicaid. Because there is no coverage option for childless adults, with the exception of Wisconsin, more than three-quarters (79%) of people in the gap are in this group.
In non-covered states , the uninsured rate is almost twice as high as in covered states (14.1% compared to 7.5%). People without insurance coverage have worse access to health care than those who are insured. One in five uninsured adults in 2022 went without needed health care because of cost, and uninsured people are less likely than those with insurance to receive preventive care and services for major health conditions and chronic diseases.
What are the characteristics of the people in the coverage area?
Nearly three-quarters of adults covered by the program are concentrated in three states in the South. Four in ten people without coverage live in Texas, which has very limited Medicaid eligibility and thus a large uninsured population (Figure 4). Another 19% of those with a gap in coverage live in Florida and 12% live in Georgia. Overall, 97% of those in the gap live in the South. Seven of the 16 states in the South have not adopted Medicaid expansion, and the region has more low-income adults without insurance and higher rates of uninsured than other regions.
People in the insurance coverage gap are disproportionately represented by people of color. Nationally, more than six in ten (62%) people who experience a gap in insurance coverage are people of color, higher than among nonelderly adults overall in states without coverage expansions (53%) and among nonelderly adults nationally (46%) (Figure 5). These differences partly explain the persistent disparities in health insurance coverage by race/ethnicity.
Despite low income, nearly six in ten people in the coverage gap are in a family with a working person, and more than four in ten are self-employed (Figure 6). Adults who work may have incomes below the poverty level because they hold low-wage jobs. People with incomes below the poverty level often do not have access to employer-provided health insurance, or if they do, it is often unaffordable. The most common occupations among adults without coverage are cashier, cook, waiter/waitress, construction worker, maid/janitor, retail salesperson, and janitor. For parents in non-covered states, even a part-time job can disqualify them from Medicaid eligibility.
Some people in the coverage gap have significant ongoing health care needs. Analysis of data from the 2022 American Community Survey shows that more than one in six (17%) people in the coverage gap have a functional disability, meaning they have serious problems with hearing, vision, cognitive function, mobility, self-care, or independent living. Even with a functional disability, many are unable to qualify for Medicaid under the disability program, leaving them uninsured. Older adults ages 55-64, when health care needs increase, make up 18% of people without insurance coverage. Studies have shown that uninsured people in this age range may not have their needs treated until they become eligible for Medicare at age 65.
How many uninsured will be able to get coverage if all states accept the expansion?
If all states adopt Medicaid expansion, approximately 2.9 million uninsured adults will become eligible for Medicaid. This number includes 1.5 million adults in the coverage gap and another 1.4 million uninsured adults with incomes between 100% and 138% FPL, most of whom are currently eligible for Marketplace coverage but are not enrolled (Figure 7 and Table 1). Most adults who are currently eligible for Marketplace coverage are eligible for plans with zero premiums; however, even in the absence of premiums, the Medicaid program may provide more comprehensive benefits and lower costs than a Marketplace plan. The potential number of people who could be covered under the Medicaid expansion varies by state.
What are the prospects for the future?
A substantial body of research continues to point to the positive effects of Medicaid expansion. reports published in 2020 and 2021 analyzed more than 600 studies and concluded that program expansion was associated with increased coverage, improved access and health, and economic benefits for states and providers. More recent studies have generally found positive effects associated with more specific outcomes, such as improved access to care, treatment and outcomes for cancer, chronic disease, sexual and reproductive health, and behavioral health. Studies also show reductions in racial disparities in coverage and access, reduced mortality, improved economic impact on providers (especially rural hospitals), and economic stability for individuals.
The American Recovery and Reinvestment Act (ARPA) provided temporary fiscal incentives for states that recently adopted Medicaid expansion. Under ARPA, states that recently adopted the expansion are eligible for an additional five percentage point increase in the state's traditional matching rate (FMAP) for two years. This incentive does not apply to expansion enrollees; states must cover 10 percent of Medicaid expansion costs and the federal government must cover 90 percent. The traditional FMAP rate applies to most expenditures for all non-expansion groups (children, parents, and eligible individuals age 65 and older or disabled); Medicaid expenditures for non-expansion groups are much higher than expenditures for the expansion group. Analysis shows that all non-expansion states would realize a net financial benefit within two years if they adopt the expansion. For the two states that recently adopted expansion, South Dakota and North Carolina, the net financial benefit would be $60 million and $1.2 billion, respectively.
Renewed debate over Medicaid expansion could lead to new states adopting the program. Legislative opposition to expanding the program may soften in some states due to financial concerns of rural hospitals as well as interest in receiving additional federal funding. If additional states expand the Medicaid program, it will help limit the increase in the number of people who will become uninsured because of the repeal of the Medicaid continuous enrollment provision. In South Dakota and North Carolina, Medicaid enrollment initially declined after the repeal of the provision began, but began to increase again after Medicaid expansion in each state.