Medicaid Expansion and Low-Income Adults with Substance Use Disorders.

Problems accessing affordable treatment are common among low-income adults with substance use disorders. A difference-in-differences analysis was performed to assess changes in insurance and treatment of low-income adults with common substance use disorders following the 2014 ACA Medicaid expansion, using data from the 2008-2017 National Surveys on Drug Use and Health. Lack of insurance among low-income adults with substance use disorders in expansion states declined from 34.8% (2012-2013) to 20.0% (2014-2015) to 13.5% (2016-2017) while Medicaid coverage increased from 24.8% (2012-2013) to 48.0% (2016-2017). In nonexpansion states, lack of insurance declined from 44.8% (2012-2013) to 34.2% (2016-2017) and Medicaid coverage increased from 14.3% (2012-2013) to 23.4% (2016-2017). Treatment rates remained low and little changed. Medicaid expansion contributed to insurance coverage gains for low-income adults with substance use disorders, although persistent treatment gaps underscore clinical and policy challenges of engaging these newly insured adults in treatment.