EDITOR’S NOTE: This article was updated on Oct. 31, 2025, to include social media comments from Mehmet Oz, administrator of the Centers for Medicare & Medicaid Services, that he posted after publication.
The Trump administration has ordered states to investigate certain individuals enrolled in Medicaid to determine whether they are ineligible because of their immigration status, with five states reporting they’ve together received more than 170,000 names collectively — an “unprecedented” step by the federal government that ensnares the state-federal health program in the president’s immigration crackdown.
Advocates say the push burdens states with duplicative verification checks and could lead people to lose coverage just for missing paperwork deadlines. But the administrator of the Centers for Medicare & Medicaid Services, Mehmet Oz, said in a post on the social platform X on Oct. 31 that more than $1 billion “of federal taxpayer dollars were being spent on funding Medicaid for illegal immigrants” in five states and Washington, D.C.
Medicaid’s overall spending topped $900 billion in fiscal year 2024.
It wasn’t clear from Oz’s statement or an accompanying video over what period the spending happened, and CMS spokespeople did not immediately respond to questions, either for an earlier version of this article or after Oz’s statement was posted.
Only U.S. citizens and some lawfully present immigrants are eligible for Medicaid, which covers low-income and disabled people, and the closely related Children’s Health Insurance Program. Those without legal status are ineligible for federally funded health coverage, including Medicaid, Medicare, and plans through the Affordable Care Act marketplaces.
At least one state said it disagreed with Oz’s comments.
“Our payments for coverage of undocumented individuals are in accordance with state and federal laws,” said Marc Williams, a spokesperson for Colorado’s Department of Health Care Policy & Financing, which administers the state’s Medicaid program. “The $1.5 million number referenced by federal leaders today is based on an incorrect preliminary finding, and has been refuted with supporting data by our Department experts.”
He added: “It is disappointing that the administration is announcing this number as final when it is clearly overstated and the conversations are very much in the education and discussion phase.”
In August, CMS began sending states the names of people enrolled in Medicaid that the agency suspected might not be eligible, demanding state Medicaid agencies check their immigration status.
KFF Health News in October reached out to Medicaid agencies in 10 states. Five provided the approximate number of names they had received from the Trump administration, with expectations of more to come: Colorado had been given about 45,000 names, Ohio 61,000, Pennsylvania 34,000, Texas 28,000, and Utah 8,000. More than 70 million people are enrolled in Medicaid.
Most of those states declined to comment further. Medicaid agencies in California, Florida, Georgia, New York, and South Carolina refused to say how many names they were ordered to review or did not respond.
Oz said in his X post that California had misspent $1.3 billion on care for people not eligible for Medicaid, while Illinois spent $30 million, Oregon $5.4 million, Washington state $2.4 million, Washington, D.C., $2.1 million, and Colorado $1.5 million.
“We notified the states, and many have begun refunding the money,” he said. “But what if we had never asked?”
Washington, D.C.’s Medicaid director, Melisa Byrd, said CMS had identified administrative expenses for the district program that covers people regardless of immigration status that should not have been billed to the federal government and her agency has already fixed some of those areas. “We run a big program that is very complex and when mistakes or errors happen, we fix them,” she said.
The program plans to pay $654,014 back to CMS by mid-November.
All five states, plus Washington, D.C., are led by Democrats, and President Donald Trump didn’t win any of them in the 2024 election.
In recent days, Deputy Health and Human Services Secretary Jim O’Neill began posting pictures on X of people he said are convicted criminals living in the U.S. without authorization who had received Medicaid benefits.
O’Neill could not be reached for comment.
“We are very concerned because this seems, frankly, to be a waste of state resources and furthers the administration’s anti-immigrant agenda,” said Ben D’Avanzo, senior health advocacy strategist with the National Immigration Law Center, an advocacy group. “This duplicates what states already do,” he said.
As part of the administration’s crackdown on people in the U.S. without authorization, President Donald Trump in February directed federal agencies to take action to ensure they are not obtaining benefits in violation of federal law.
In June, advisers to Health and Human Services Secretary Robert F. Kennedy Jr. ordered CMS to share information about Medicaid enrollees with the Department of Homeland Security, drawing a lawsuit by some states alarmed that the administration would use the information for its deportation campaign against unauthorized residents.
In August, a federal judge ordered HHS to stop sharing the information with immigration authorities.
State Medicaid agencies use databases maintained by the Social Security Administration and Department of Homeland Security to verify enrollees’ immigration status.
If states need to go back to individuals to reverify their citizenship or immigration status, it could lead some to fall off the rolls unnecessarily — for example, if they don’t see a letter requesting paperwork or fail to meet a deadline to respond.
“I am not sure that evidence suggests there really is a need for this” extra verification, said Marian Jarlenski, a health policy professor at the University of Pittsburgh School of Public Health.
Oz made clear that the Trump administration disagrees.
“Whether willful or not, the states’ conduct highlights a terrifying reality: American taxpayers have been footing the bill for illegal immigrants’ Medicaid coverage, despite many Democrats and the media insisting otherwise,” Oz said in his X post.
In an August press release, CMS said it would ask states to verify eligibility for enrollees whose immigration status could not be confirmed via federal databases. “We expect states to take quick action and will monitor progress on a monthly basis,” the agency said.
Leonardo Cuello, a research professor at Georgetown University’s Center for Children and Families, called the CMS order to states “unprecedented” in the Medicaid program’s 60-year history.
He said the federal government may have been unable to verify certain individuals’ immigration status because names were misspelled or outdated, such as when a beneficiary is identified by their maiden instead of married name. The names may also include people helped by Emergency Medicaid, a program that covers the cost of hospital emergency services, including labor and delivery, for people regardless of immigration status.
“CMS is conducting pointless immigration status reviews for people whose hospital bills were paid by Emergency Medicaid,” Cuello said.
Oz noted in his post that federal law “does permit states to use Medicaid dollars for emergency treatment, regardless of patients’ citizenship or immigration status,” and that states can “legally build Medicaid programs for illegal immigrants using their own state tax dollars, so long as no federal tax dollars are used.”
The states Oz mentioned all run their own such programs.
The verification checks create an added burden for state Medicaid agencies that are already busy preparing to implement the tax and policy law Trump signed in July. The measure, which Republicans call the One Big Beautiful Bill Act, makes many changes to Medicaid, including adding a work requirement in most states starting by 2027. The law also requires most states to more frequently check the eligibility of many adult Medicaid enrollees — at least twice a year.
“I fear states may do unnecessary checks that create a burden for some enrollees who will lose health coverage who should not,” Cuello said. “It’s going to be a whole lot of work for CMS and states for very little pay dirt.”
Cuello said the effort may have “greater political value than actual value.”
Brandon Cwalina, a spokesperson for the Pennsylvania Department of Human Services, which runs Medicaid in the state, said the state already requires every Medicaid applicant to verify their citizenship or, where applicable, their eligible immigration status.
However, he said, the directive issued by CMS “constitutes a new process, and DHS is carefully reviewing the list in order to take appropriate actions.”
Oz did not name Pennsylvania, which Trump won in 2024, in his post.
If a lawful resident does not have a Social Security number, the state confirms their legal status by checking a database from Homeland Security, as well as verifying specific immigration documents, he said.
Other state Medicaid agencies said they also needed to regroup before reaching out to enrollees.
“Our teams just received this notice and are working through a process by which we will perform these reviews,” Jennifer Strohecker, then Utah’s Medicaid director, told a state advisory board in August.
Renuka Rayasam and Rae Ellen Bichell contributed reporting.
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