Shover CL, et al. - Researchers examined the change in the proportion of United States substance use disorder (SUD) treatment sites offering treatment for psychiatric comorbidities following Medicaid expansion as part of the implementation of Affordable Care Act in 2014 using panel data from the 2013–2014, n = 660, and 2016–2017, n = 638, waves of the National Drug Abuse Treatment System Survey. States that expanded Medicaid showed an increase in the proportion of United States SUD treatment facilities offering antidepressants and other psychiatric medication to treat mental health comorbidities. Following Medicaid expansion, the largest increase in offering psychiatric medication was observed in residential treatment facilities. The proportion of SUD treatment facilities offering behavioral treatment for mental health comorbidities appeared unchanged following Medicaid expansion.