States across the U.S. experienced substantial declines in Affordable Care Act (ACA) enrollment over the past year, with Ohio and Oklahoma each losing nearly one-third of their enrollees, according to new federal data. The figures provide the first comprehensive 50-state breakdown of enrollment decreases that occurred after enhanced subsidies expired in January.

The data, released by the Trump administration in late June, indicates that approximately 2.6 million fewer Americans held ACA plans in February compared to the same period last year. This count includes individuals who enrolled or were automatically re-enrolled and subsequently paid their initial monthly premiums to maintain coverage. The data also accounts for individuals retroactively removed from coverage after a non-payment grace period concluded.

"This is the first time we’ve seen state-level data that shows how much ACA marketplace enrollment truly fell," said Cynthia Cox, a vice president at the healthcare research nonprofit KFF. "It’s in line with our expectations, but it does show a very steep drop in the number of people with ACA coverage."

Health analysts have been closely monitoring ACA enrollment changes since the expiration of enhanced premium tax credits, which led to significant increases in monthly insurance costs for many Americans, prompting some to abandon coverage. The renewal of these subsidies was a contentious issue in Congress.

Health insurance costs have been rising across ACA and other insurance programs, occurring at a time when affordability is a primary concern for voters in the upcoming November elections. The U.S. Department of Health and Human Services suggested a federal crackdown on fraudulent enrollment could be a factor in the enrollment drop. However, analysts largely attribute the decline to the expiration of federal subsidies and other changes, such as stricter requirements for immigrants accessing subsidized plans.

State-Level Enrollment Declines

An analysis of the data shows that Ohio and Oklahoma experienced the most significant enrollment drops, with each state seeing a decline of more than 32% in ACA enrollment over the past year. Arizona, South Carolina, Minnesota, Indiana, Michigan, Mississippi, Louisiana, and Missouri also saw substantial losses, each losing more than a quarter of their enrollees.

Florida, which has a high reliance on ACA insurance and did not expand Medicaid, still maintains the largest number of marketplace enrollees with nearly 4 million residents. However, the state recorded the highest number of individuals dropping coverage this year, totaling around 443,000.

The data does not specify whether those who lost ACA coverage obtained insurance through other means, such as employer plans. However, Cox noted that most individuals who leave the marketplace are likely uninsured, as it typically serves as a last resort for those ineligible for other coverage options.

Several states that experienced the largest enrollment decreases were also those that saw the most significant enrollment gains after the introduction of enhanced federal subsidies during the COVID-19 pandemic. This suggests that the affordability provided by the enhanced subsidies attracted a large number of enrollees in those states.

Only New Mexico reported an increase in its covered population, gaining approximately 14% more enrollees compared to the previous year. The state uniquely offset the loss of federal subsidies by using its own funds.

Federal vs. State Marketplaces

Approximately three-fifths of states utilize the federal Healthcare.gov marketplace, while the remainder operate their own state-based exchanges. The new data indicates that states using the federal marketplace experienced larger overall declines in enrollees compared to those with state-based exchanges. This disparity may be due to proactive measures taken by states with their own marketplaces to mitigate costs for residents following the subsidy expiration.

New Mexico's legislative action to allocate state funds to cover the gap in subsidies through mid-2026, later extended through mid-2027, exemplifies the efforts made by some states to maintain coverage affordability.