The administration says its review uncovered widespread problems involving improper eligibility, questionable applications and so-called “phantom” enrollments.
Federal officials estimate that improper, phantom or fraudulent enrollment reached 5.6 million people in 2025. Through February 2026, the administration said it had prevented approximately 1.5 million people from receiving subsidies they did not qualify for and ended or blocked another 1.4 million enrollments.
That adds up to approximately 2.9 million people who had previously been receiving subsidies that officials determined they should not have received.
But the administration says the cleanup is far from finished.
Officials estimate another 2.6 million improper or phantom enrollments remain. More than 1 million of those enrollments reportedly involve individuals without a Social Security number, according to the administration’s own estimate.
A Trump administration official cited by Fox News estimated that the alleged abuse represented approximately $10 billion annually in taxpayer exposure between 2021 and 2024.
The administration has responded by restoring or strengthening several verification procedures.
Those measures include renewed income verification, additional checks for duplicate Medicaid coverage, tighter scrutiny of special enrollment opportunities and investigations into brokers suspected of creating unauthorized or phantom enrollments.
The issue is particularly significant because some of the alleged misconduct involves insurance agents and brokers.
In some cases, officials say brokers enrolled people in coverage or altered their plans without obtaining proper authorization. The alleged practice could allow brokers to receive compensation while leaving consumers unaware that changes had been made to their insurance.
That concern is not limited to the Trump administration’s investigation.
A separate Government Accountability Office review found that at least 160,000 federal Marketplace applications during plan year 2024 had likely unauthorized changes made by agents or brokers. The watchdog warned that consumers could suffer serious consequences, including unexpected costs or losing access to medications and other medical care.
The GAO findings add another layer to the controversy surrounding Obamacare’s enrollment system.
If consumers can have their plans altered without authorization, the consequences go well beyond government accounting. A person could discover only after receiving a medical bill that his or her deductible, copayments, network or coverage had changed.
The Trump administration argues that stronger controls are necessary to protect both taxpayers and legitimate Obamacare customers.
“Preserving the fiscal and programmatic integrity of the ACA Exchanges is key to safeguarding taxpayer-funded resources for those that truly need them,” the administration’s report says.
The report also states: “The federal government paying brokers to enroll individuals without their knowledge is not.”
Health and Human Services Secretary Robert F. Kennedy Jr. and Centers for Medicare and Medicaid Services Administrator Dr. Mehmet Oz have made combating waste and fraud a major part of the administration’s health care agenda.
For Republicans, the enrollment investigation strengthens an argument they have made for years: Government programs can become vulnerable when eligibility requirements and verification systems are loosened.
The Biden administration’s expansion of ACA subsidies and enrollment opportunities dramatically increased participation in the program. The Trump administration is now arguing that part of that growth was driven not simply by Americans seeking coverage, but also by questionable enrollment practices that taxpayers ultimately financed.
Democrats, however, have defended Obamacare subsidies as an important tool for keeping health insurance affordable for millions of Americans.
That debate is now colliding with the administration’s fraud crackdown.
The numbers will likely become ammunition in the fight over whether federal subsidies should be extended, reduced or redesigned. Republicans can point to millions of questionable enrollments and billions of dollars in estimated taxpayer exposure as evidence that the system requires stronger safeguards.
The administration’s figures also come with an important caveat: being flagged as improper or phantom does not necessarily mean every individual involved intentionally committed fraud. The government’s categories include questionable or unauthorized enrollments that still require investigation and correction.
Even with that distinction, the scale of the problem is difficult to dismiss.
Nearly 3 million enrollments have already been blocked or terminated from receiving subsidies, while the administration estimates another 2.6 million improper or phantom enrollments could remain.
At the same time, the GAO has independently documented serious weaknesses involving unauthorized changes by agents and brokers.
For a federal health care system that relies on billions of taxpayer dollars, those findings create an uncomfortable question for Washington: How many Americans were actually receiving legitimate assistance, and how much taxpayer money was flowing through a system that lacked adequate safeguards?
The Trump administration says it intends to find out.
And as officials continue auditing the Obamacare rolls, the battle over the Affordable Care Act is moving beyond the familiar argument over premiums and coverage.
It is becoming a fight over something taxpayers may care about just as much: whether the government can prove that the money it spends is going to the people who actually qualify for it.
