WASHINGTON DC. WA, September 23, 2026 — Plans by federal health officials to deny coverage to hundreds of thousands of Affordable Care Act enrollees this year. Those removals hit signups that the Centers for Medicare and Medicaid Services deems improper, duplicate, or phantom. Under the new review process, insurers have already identified small groups of large batches of policyholders for disenrollment.
Scale of the Crackdown
CMS projected that up to 5.6 million people would have been unjustifiably enrolled in marketplace plans by 2025. The agency has already been weeding out about 2.9 million of those enrollees by imposing stricter verification rules, it said. Oscar Health has identified as many as 300,000 of its own members who could face disenrollment.
CMS Administrator Mehmet Oz has portrayed the effort as reclaiming “the exchanges’ integrity.” They are aimed at saving taxpayer money and giving subsidies only to those eligible, he says. Critics say the review process is based on presumptions that indiscriminately capture the innocent along with criminals.
Why the Numbers Are Disputed
Health policy researchers suggest those estimates of fraud by the administration may exaggerate the depth of it. Matthew Fiedler, a fellow at the Brookings Institution, called the idea that fraud accounts for all of the decrease in enrollment “not even close to believable.” Instead, he cites the end of expanded premium tax credits as a more likely culprit.
Enrollment has fallen since January, when 23.1 million were enrolled on ACA exchanges. According to Department of Health and Human Services figures, that number dropped in February to about 19.2 million. Many plans also have their premiums raising even more this enrollment period.
What Triggered the Review
This effort comes after a rule from 2025 effectively reversed a policy of permitting low-income applicants to enroll year-round with little verification during the Biden administration. And that leeway, officials say, gave brokers an opportunity to sign people up without them knowing about it—or even wanting it. The Centers for Medicare and Medicaid Services (CMS) claims it received almost 342,000 wrong sign-up complaints of this type in 2025.
A federal court in Maryland temporarily blocked parts of the larger integrity rule before HHS appealed. This is an ongoing legal fight while CMS continues to hold disenrollment reviews at the level of individual insurers. Insurers say they are working through lists they received from the CMS to identify which claims were actually fraudulent.
What Enrollees Should Do
Anyone who receives a disenrollment letter should immediately contact their insurer to confirm whether they still have coverage. Policyholders who believe they were wrongly flagged can appeal through their state or federal marketplace. Missing that window might create a gap in coverage as an appeal plays out.
Consumer advocates urge anyone signing up to save copies of enrollment confirmations and premium payment records in case any questions arise. A new open enrollment looks likely to face closer scrutiny as CMS maintains its push over verification. The fate of coverage for many millions of families will be decided over the coming months—during a continued and expanded crackdown.
Insurance brokers say they’ve already received a wave of calls from confused policyholders who don’t know whether they have been affected. Several said its callers were hard to get, prompting some to turn only if they matter—point out and call themselves fact much as email state marketplace call centers. That logjam has meant extra pressure on enrollees whom the law requires to correct their status before they’re allowed to go completely off coverage.
Patient advocacy groups caution that even a brief lapse in coverage can interfere with refilling continuous medications or receiving planned therapies. They are telling enrollees not to wait for written notice of any change in their status and instead act quickly. Some clinics have been holding free enrollment assistance sessions for patients affected by the review.
CMS faces pressure from Democrats and Republicans to disclose more about how it determines whether certain groups will be removed from coverage. What isn’t clear, though, is whether that pressure results in any revised procedures as the agency completes its review throughout the fall. For the time being, most of that is left to individual enrollees to verify and advocate for their own coverage.
