With Donald Trump returning to the White House and Republicans gaining complete control of Congress in 2025, the Affordable Care Act’s Medicaid expansion is once again under threat.
According to KFF, a health information nonprofit that includes KFF Health News and the Georgetown University Centre for Children and Families, more than 3 million adults in nine states would be at immediate risk of losing their health insurance if the GOP reduced the additional federal Medicaid funding that has allowed states to expand eligibility.
That’s because states have trigger laws in place to quickly end Medicaid expansions if federal funding is cut off.
The states are: Arizona, Arkansas, Illinois, Indiana, Montana, New Hampshire, North Carolina, Utah, and Virginia.
The 2010 Affordable Care Act encouraged states to expand Medicaid programs to cover more low-income Americans who did not have employer-provided health insurance.
Since 2014, forty states and the District of Columbia have agreed to extend health insurance to an estimated 21 million people, helping to drive the uninsured rate in the United States to record lows.
In exchange, the federal government pays 90% of the cost of covering the larger population. This is significantly higher than the federal match for other Medicaid beneficiaries, which averages around 57% nationally.
Conservative policy groups, which have generally opposed the ACA, argue that the program is too expensive and covers too many people. Democrats argue that the Medicaid expansion has saved lives and benefited communities by providing coverage to people who could not afford private insurance.
Renuka Tipirneni, an associate professor at the University of Michigan’s School of Public Health, said that if Congress cuts federal funding, Medicaid expansion would be jeopardised in all states that have opted into it, including those without trigger laws, because state legislatures would be forced to make up the difference.
Tipirneni stated that the decision to continue or reverse the expansion would be influenced by state politics.
For example, Michigan approved a trigger as part of its Medicaid expansion in 2013, when the state was led by a Republican governor and legislature. Last year, when Democrats controlled the government, the state eliminated its funding trigger.
Six of the nine states with trigger laws (Arizona, Arkansas, Indiana, Montana, North Carolina, and Utah) supported Trump in the 2024 election.
The majority of the nine states’ triggers kick in if federal funding falls below 90%. Arizona’s trigger would prevent expansion if funding fell below 80%.
Montana’s law limits expansion below 90% funding but allows it to continue if lawmakers find additional funding. Montana lawmakers must reauthorise the Medicaid expansion or it will be terminated, according to state law.
Researchers at KFF and the Georgetown Centre estimate that between 3.1 million and 3.7 million people would lose coverage quickly in states with triggers.
The difference is determined by how states treat people who were added to Medicaid prior to the ACA expansion; they may continue to be eligible even if the expansion ends.
Three other states, Iowa, Idaho, and New Mexico, have laws requiring their governments to mitigate the financial impact of losing federal Medicaid expansion funding, but they do not automatically end expansions.
KFF estimates that 4.3 million Medicaid expansion enrollees would lose coverage if those three states were included.
The ACA authorised Medicaid expansions for adults with incomes up to 138% of the federal poverty level, or approximately $20,783 per person in 2024.
Due to Medicaid expansions, nearly a quarter of the 81 million people enrolled in the program now participate.
“With a reduction in the expansion match rate, it is likely that all states will need to evaluate whether to continue expansion coverage because it would require a significant increase in state spending,” said Robin Rudowitz, vice president and director of KFF’s Program on Medicaid and the Uninsured.
“If states drop coverage, it is likely that there would be an increase in the number of uninsured, and that would limit access to care across red and blue states that have adopted expansion.”
After granting eligibility for social programs such as Medicaid, states rarely reduce it.
The triggers make it politically easier for state lawmakers to end Medicaid expansion because they do not have to take any new action to reduce coverage, according to Edwin Park, a research professor at Georgetown University’s Centre for Children and Families.
To understand the impact of trigger laws, consider what happened after the Supreme Court overturned Roe v. Wade in 2022, and thus the constitutional right to abortion.
Conservative lawmakers in 13 states had crafted trigger laws that would automatically impose bans if the national right to abortion were overturned. These state laws resulted in restrictions that went into effect immediately or shortly after the court ruling.
States implemented triggers as part of Medicaid expansion to persuade lawmakers that putting state dollars at risk for a federal program that is unpopular with the majority of Republicans.
It’s unclear what Trump and congressional Republicans will do with Medicaid after he takes office in January, but one sign could be a recent recommendation from the Paragon Health Institute, a leading conservative policy organisation led by former Trump health adviser Brian Blase.
Paragon proposes that the federal government reduce the 90% federal match for expansion beginning in 2026 until 2034, when it will be equal to each state’s federal match for traditional enrollees.
Under that plan, states could still receive ACA Medicaid expansion funding while limiting coverage to enrollees with incomes up to the federal poverty line. Currently, in order to receive expansion funding, states must provide coverage to everyone up to 138% of the poverty line.
According to Daniel Derksen, director of the University of Arizona’s Centre for Rural Health, Arizona is unlikely to eliminate its trigger in order to compensate for lost federal funding. “It would be a tough sell right now as it would put a big strain on the budget,” he told me.
Republican lawmakers in Washington have previously targeted Medicaid. Republican congressional leaders proposed legislation in 2017 to reduce federal expansion funding, which would have shifted billions of dollars to states. That plan, part of a larger strategy to repeal Obamacare, ultimately failed.