Affordable Care Act enrollment has exploded over the last few years, more than doubling, with much of the growth coming from states that voted for Donald Trump in 2024, a KFF analysis finds.
The top 15 states with the most growth in the ACA marketplace since 2020 were all won by President Trump last year. An earlier KFF analysis showed that states that had not expanded Medicaid, and those that started off with high uninsured rates, saw the most growth in ACA marketplace enrollment.
Those states are Alabama, Arkansas, Arizona, Florida, Georgia, Iowa, Indiana, Kansas, Kentucky, Louisiana, Michigan, Missouri, Mississippi, Ohio and Tennessee.
In states that currently have not expanded Medicaid, Marketplace enrollment grew 188% from 2020 to 2025, compared with the 65% growth in expansion states. In states where uninsured rates for children and adults under 65 were at least 10% in 2019, ACA Marketplace enrollment increased by 168% since 2020, whereas states with lower uninsured rates saw enrollment grow by 50%.
WHAT'S THE IMPACT?
Much of the marketplace growth has been fueled by enhanced tax credits, according to KFF. These are set to expire at the end of this year, unless Congress votes to extend them.
The enhanced tax credits have increased the affordability of coverage and newly extended financial assistance to middle-income enrollees making above 400% of the federal poverty level (FPL). Had it not been for the enhanced subsidies, analysts said annual premium payments for subsidized enrollees in 2024 would have been $705 (79%) higher, on average, up from $888 to $1,593.
The Congressional Budget Office estimates that the cost of permanently extending the enhanced subsidies would be $335 billion over a 10-year period. If the enhanced subsidies are not renewed, it is expected that 3.8 million more people would become uninsured.
CBO also projects that the loss of enhanced subsidies would prompt healthy enrollees to leave the ACA marketplace and, consequently, insurers to increase the sticker price of premiums.
THE LARGER TREND
With Republican control of Congress and tax subsidies expiring at the end of 2025, millions of Americans may be at risk of losing enhanced subsidies that currently underwrite the cost of their health insurance through the Affordable Care Act's marketplaces, according to industry experts and the Congressional Budget Office, said CBS.
In January, data published by KFF showed upward of 44 million people, or 16.4% of the non-elderly U.S. population, have been covered by an Affordable Care Act initiative, including health plan enrollment and Medicaid expansion.
In 2024, marketplace enrollment hit a record high of 21.4 million people (almost double the 11 million enrolled in 2020), Medicaid expansion enrollment was 21.3 million (a 41% increase from 2020), and BHP enrollment in 2024 was 1.3 million (up from 880,000 in 2020).
KFF attributed much of the marketplace growth since 2020 to enhanced subsidies under the American Rescue Plan Act in 2021, which were renewed through 2025 by the Inflation Reduction Act. These subsidies, KFF said, reduced premium payments across the board for ACA Marketplace enrollees – including $0 monthly premiums for enrollees with incomes up to 150% of the FPL – and made some middle-income people who had previously been priced out of coverage newly eligible for financial assistance.
Jeff Lagasse is editor of Healthcare Finance News.
Email: jlagasse@himss.org
Healthcare Finance News is a HIMSS Media publication.