Section 1115 Substance Use Disorder Waivers: Opportunities and Limitations.

In 2022, 48.7 million people in the United States (17.3% of the population aged 12 or older), met criteria for substance use disorder (SUD). Nearly 40% of people with opioid use disorder (OUD) are Medicaid recipients, making Medicaid the largest single source of OUD treatment insurance coverage. Despite this crucial importance, there remain two major barriers to expanding access to treatment for persons with SUD baked into the program: the Institutions for Mental Diseases (IMD) exclusion and the Medicaid inmate exclusion. In this essay we first provide a timeline of these two waiver reforms to illustrate the variation in waivers over time and across states. Second, we assess the evidence to date on how well the SUD waivers are working to accomplish these goals in states that have adopted them. This review will focus on the SUD waivers that address the IMD exclusion, because the MIE waivers are too new for any systematic evidence. We will then consider outstanding implementation challenges and policy risks associated with the IMD and MIE waivers, and conclude by considering challenges these waivers do not address and therefore demand particular attention to properly serve persons living with SUD.