This record level of enrollment was made possible by enhancements in the Inflation Reduction Act, which built on the Affordable Care Act and the American Rescue Plan Act to expand advanced premium tax credits (APTCs). APTCs offer financial assistance for consumers enrolling in individual health insurance coverage on the ACA marketplace. Eligibility for APTCs was previously capped at 400 percent of the federal poverty level. However, the expansions offered by the American Rescue Plan Act and Inflation Reduction Act protect all individuals and families with marketplace coverage who have annual household incomes at or above 400 percent of the federal poverty level from spending more than 8.5 percent of their household income on premiums for silver benchmark plans until the end of 2025.

ACA marketplaces have also recently seen an infusion of enrollment as a result of the “unwinding” of the Families First Coronavirus Response Act of 2020’s continuous coverage provision for Medicaid, which required state Medicaid programs to maintain coverage for people enrolled in Medicaid through the end of the COVID-19 public health emergency. Between March 31, 2023, and April 4, 2024, states disenrolled nearly 20 million people from Medicaid. These numbers are likely an underestimate, though, as one-third of renewal outcomes have yet to be reported. As part of this process, some states have taken action to smooth transitions from Medicaid to marketplace coverage. In October 2023, about 1.3 million Medicaid enrollees transitioned to marketplace plans, and many of them were able to obtain coverage with APTCs.

Without congressional action, the enhanced financial assistance supporting record ACA marketplace enrollment will expire at the end of 2025.

A new CAP analysis explores how plan selections in the 32 states that use the federally facilitated marketplace (HealthCare.gov), along with Vermont and the District of Columbia, varied by congressional district during open enrollment for the 2024 plan year. For example, 1 in 17 people under the age of 65 in Arizona’s 6th district selected marketplace plans, with 86 percent receiving APTCs; 1 in 16 nonelderly people in Michigan’s 10th district selected marketplace plans, with 89 percent receiving APTCs; 1 in 7 nonelderly people in North Carolina’s 1st district selected marketplace plans, with 97 percent receiving APTCs; and a similar 1 in 7 nonelderly people in Utah’s 4th district selected marketplace plans, with 95 percent receiving APTCs.

In some districts, large proportions of people elected to get their insurance through the marketplace. In these districts, a failure to extend current APTC enhancements could have significant consequences. For instance, In Florida’s 26th district, nearly 1 in 2 people under the age of 65 selected marketplace plans—99 percent of whom would receive APTCs for the 2024 plan year. Notably, Florida, along with six other states included in this analysis, has not expanded Medicaid , likely driving some low-income people who would have otherwise qualified for Medicaid expansion to the ACA marketplace for coverage.

Use the interactive below to see the number of people who selected marketplace plans for the 2024 plan year, including how many would receive APTCs in congressional districts in the 32 states that participated in the federally facilitated marketplace. State- and district-level data for the District of Columbia and Vermont were also included because they both have only one congressional district. Data for other state-based marketplaces were not available at the time of this publication. The total number of people under the age of 65 for each district was taken from the U.S. Census Bureau’s 2022 American Community Survey .*