Nearly half of ACA Medicaid expansion enrollees were ineligible in 2024: Paragon study

A new study from the Paragon Health Institute estimates that 9.2 million people enrolled through the Affordable Care Act's Medicaid expansion in 2024, which is nearly 46 percent of all expansion enrollees, did not meet federal eligibility requirements.

The report authored by Liam Sigaud and released Monday finds the ineligible expansion enrollees rose dramatically from its 4.9 million (33 percent) figure in 2019. The federal government paid an estimated $32.9 billion for this improper enrollment in 2024 alone.

California accounted for a disproportionate share, with around 3.1 million improper enrollees and an estimated ineligibility rate of 62 percent. New York and several other expansion states also showed elevated issues with the eligibility rates. The study blames much of the growth on weak state incentives under the program’s money structure, which provides a 90 percent federal match for expansion enrollees compared with roughly 60 percent for traditional Medicaid beneficiaries.

These numbers come as the Trump administration has been stepping up efforts to tighten oversight of federal health programs, while arguing that the stronger verification and anti-fraud measures are reducing improper enrollments. Administration officials have pointed to declining Affordable Care Act enrollment as evidence the crackdown is working, while some state-run operations contend the drop is largely driven by the expiration of premium subsidies. Some states have maintained that higher premiums have pushed some middle-income Americans and lawfully present immigrants to switch to lower-cost plans with significantly higher deductibles, highlighting an ongoing debate over whether falling enrollment reflects improved program integrity or rising insurance costs.

State officials, on the other hand, have maintained that the higher premiums have made middle- and lower-income Americans and lawfully present migrants either drop their health coverage or transition to lower-cost plans with deductibles that are significantly higher than before. While the White House maintains its reforms are restoring the integrity of the programs, some insurers have said that overall enrollment could continue to decline as consumers are faced with rising premiums.