About 44 million people were covered under one of the Affordable Care Act's (ACA's) initiatives, from the insurance marketplaces to Medicaid expansion, according to a new report from the KFF.
That means about 16.4% of nonelderly U.S. adults have gained coverage under these ACA reforms. Marketplace enrollment, for example, set a new record last year, reaching 21.4 million, nearly doubling from the 11 million people enrolled in an exchange plan in 2020.
In addition, Medicaid expansion coverage grew as additional states expanded their programs. The report said 21.3 million people were covered under expanded Medicaid in 2024, up by about 41% from 2020.
While enrollment in basic health programs is lower than the two marquee programs, 1.3 million were under one of these programs, up from 880,000 in 2020.
There are multiple factors contributing to these growth numbers, according to the report. For one, enhanced premium subsidies was the primary driver in the record-breaking sign-ups through the exchanges.
However, those tax credits are set to expire at the end of this year, which could drive people out of the individual market. The KFF estimates that enrollees' premium payments will increase by 75% on average if the subsidies are not renewed by Congress at some point this year. It could also lead to 3.8 million people becoming uninsured, per the report.
A new administration in the White House and changes in Congress also have implications for expanded Medicaid. The report said that 4.3 million people are enrolled in states that have a trigger law in place, which would either end the expansion or force a review should federal funding be reduced.
Officials appointed for key roles by President-elect Donald Trump have also emphasized making cuts to entitlements and other spending to reduce the overall size of the government. The KFF report noted that the 10 states that saw the largest growth in ACA program enrollment between 2020 and 2024 were all won by Trump in the 2024 election, and none had expanded their Medicaid programs prior to 2020.
"The uninsured rate hit an historic low in 2023 as coverage through the ACA and Medicaid increased, but these coverage gains may not last for long," the KFF researchers wrote.