Highly vulnerable communities and the Affordable Care Act: Health insurance coverage effects, 2010–2018

Initially implemented in 2014 in some U.S. states, the Medicaid expansions under the Affordable Care Act (ACA) aimed to make health insurance coverage more accessible to the low-income population. This paper aims to quantify the impact of the ACA Medicaid expansions on insurance coverage among racial/ethnic minorities, immigrants, single mothers, veterans, and low-education whites—i.e., the sectors of the population identified with some of the highest healthcare needs. We focus on individuals 18–64 years of age earning 138% or less of the federal poverty level from the American Community Survey, 2010–2018 (n = 2,927,402). We use difference-in-differences (DD) and difference-in-difference-in-differences (DDD) approaches with propensity scores matched comparison groups to estimate pre-post ACA insurance coverage differences between individuals living in states that participated in the ACA Medicaid expansions and those living in non-participating states, and to estimate if such differences vary across subgroups. We find that insurance coverage rates increased for all subgroups; yet, the ACA benefits have not been evenly distributed across them. Low-education whites, non-Hispanic whites, females, and non-Hispanic Native Americans exhibited the highest improvements in insurance coverage. Our results contribute to the understanding of recent trends in racial and socioeconomic disparities in healthcare and the appropriate policy prescriptions to ameliorate them.