Impacts of the Affordable Care Act Medicaid Expansion on Mental Health Treatment Among Low-income Adults Across Racial/Ethnic Subgroups, 2010-2017

This study examines whether the Affordable Care Act (ACA) Medicaid expansion (ME) was associated with changes in racial/ethnic disparities in insurance coverage, utilization, and quality of mental health care among low-income adults with probable mental illness using the National Survey on Drug Use and Health with state identifiers. This study employed difference-in-difference models to compare ME states to non-expansion states before (2010-2013) and after (2014-2017) expansion and triple difference models to examine these changes across non-Hispanic White (NHW), non-Hispanic Black (NHB), and Hispanic/Latino racial/ethnic subgroups. Insurance coverage increased significantly for all racial/ethnic groups in expansion states relative to non-expansion states (DD: 9.69; 95% CI: 5.17, 14.21). The proportion low-income adults that received treatment but still had unmet need decreased (DD: -3.06; 95% CI: -5.92, -0.21) and the proportion with unmet need and no mental health treatment increased (DD: 2.38; 95% CI: 0.03, 4.73). ME was not associated with reduced disparities.