Who Enrolls in Coverage and Who Remains Uninsured? Medicaid Take-Up Before and After the Affordable Care Act and During Unwinding

Abstract

Context Many uninsured individuals in the U.S. are eligible for Medicaid but not enrolled. The Affordable Care Act (ACA) expanded Medicaid eligibility starting in 2014, streamlined enrollment, and boosted outreach. During the 2020 COVID-19 pandemic, states were required to provide continuous coverage to Medicaid enrollees, a policy that ended in April 2023, with resulting coverage losses during the “unwinding” of this policy. Methods Using household data from the American Community Survey and state-level eligibility criteria, we assessed Medicaid participation among U.S. citizens under age 65, who either had Medicaid coverage or no insurance. We compared results before the ACA (2008-2010), after the ACA (2017-2019), and during “unwinding” (2023). We utilized logistic regression to identify predictors of take-up in each of these time periods. Findings The national take-up rate among Medicaid-eligible individuals rose from 76.5% before the ACA to 85.0% after the ACA. These gains persisted in 2023 as unwinding began, when take-up was slightly higher (86.5%) than before the pandemic. Post-ACA participation was highest among eligible children; Asian American, Pacific Islander, and Native Hawaiian (AANHPI) and Black individuals; and residents of expansion states. Participation was lowest among adults ages 19-21, American Indian and Alaska Native (AIAN) individuals, employed adults, and those facing premiums for Medicaid coverage. Take-up improved post-ACA in both more and less deprived neighborhoods, while urban areas saw greater growth in take-up than rural areas. Conclusions From the pre- to post-ACA period, Medicaid take-up rates among eligible individuals increased, and these gains persisted during the beginning of the unwinding period, potentially reflecting increased outreach efforts under the Biden Administration. However, areas of vulnerability remain among young adults, working adults, AIAN individuals, and those in rural areas. These findings have important implications as the unwinding period ends and large changes to Medicaid may be considered after the 2024 elections.