Impact Of Medicaid Expansion On Coverage And Treatment Of Low-Income Adults With Substance Use Disorders.

Extensive undertreatment of substance use disorders has focused attention on whether the expansion of eligibility for Medicaid under the Affordable Care Act (ACA) has promoted increased coverage and treatment of these disorders. We assessed changes in coverage and substance use disorder treatment among low-income adults with the disorders following the 2014 ACA Medicaid expansion, using data for 2008-15 from the National Survey on Drug Use and Health. The percentage of low-income expansion state residents with substance use disorders who were uninsured decreased from 34.4 percent in 2012-13 to 20.4 percent in 2014-15, while the corresponding decrease among residents of nonexpansion states was from 45.2 percent to 38.6 percent. However, there was no corresponding increase in overall substance use disorder treatment in either expansion or nonexpansion states. The differential increase in insurance coverage suggests that Medicaid expansion contributed to insurance gains, but corresponding treatment gains were not observed. Increasing treatment may require the integration of substance use disorder treatment with other medical services and clinical interventions to motivate people to engage in treatment.