Health Insurance and Mental Health Treatment Use Among Adults With Criminal Legal Involvement After Medicaid Expansion

Objective: Individuals with criminal legal involvement have high rates of substance use and other mental disorders. Before implementation of the Affordable Care Act's Medicaid expansion, they also had low health insurance coverage. The objective of this study was to assess the impact of Medicaid expansion on health insurance coverage and use of treatment for substance use or other mental disorders in this population. Methods: The authors used restricted data (2010-2017) from the National Survey on Drug Use and Health (NSDUH). Using a difference-in-differences approach, the authors estimated the impact of Medicaid expansion on health insurance coverage and treatment for substance use or other mental disorders among individuals with recent criminal legal involvement. Results: The sample consisted of 9,910 NSDUH respondents who were ages 18-64 years, had a household income <= 138% of the federal poverty level, and reported past-year criminal legal involvement. Medicaid expansion was associated with an 18 percentage-point increase in insurance coverage but no change in receipt of substance use treatment among individuals with substance use disorder. Individuals with any other mental illness had a 16 percentage-point increase in insurance coverage but no change in receipt of mental health treatment. Conclusions: Despite a large increase in health insurance coverage among individuals with criminal legal involvement and substance use or other mental disorders, Medicaid expansion was not associated with a significant change in treatment use for these conditions. Insurance access alone appears to be insufficient to increase treatment for substance use or other mental disorders in this population.