Medicaid Expansion and Availability of Opioid Medications in the Specialty Substance Use Disorder Treatment System

Objective: Research has examined the effect of Medicaid expansion on access to physicians with buprenorphine waivers, but less attention has been paid to Medicaid's impact on opioid use disorder medication availability within the specialty substance use disorder treatment system. To address this gap in the literature, this study examined the impact of Medicaid expansion on availability of opioid medications in specialty programs. Methods: This study used data from the National Survey of the Substance Abuse Treatment Services (2002-2017), containing all known substance use disorder treatment programs in the United States, to examine the effect of Medicaid expansion on the availability of opioid use disorder-medications by treatment program ownership type (publicly owned, private for profit, and private nonprofit) among opioid treatment programs (OTPs) and nonOTPs. Results: The effects of Medicaid expansion were limited to nonprofit and for-profit OTPs. Medicaid expansion was associated with 135.1% and 57.5% increases in the number of nonprofit and for-profit OTPs offering injectable naltrexone, respectively, and with a 64.4% increase in the number of nonprofit OTPs offering buprenorphine. Nonprofit and for-profit OTPs compose,10% of the treatment system, indicating that improvements in opioid use disorder treatment associated with Medicaid expansion were limited to a small share of the specialty system. Conclusions: The limited impact of Medicaid expansion on the specialty treatment system may perpetuate disparities in the accessibility and quality of opioid use disorder treatment for Medicaid enrollees and fail to alleviate high rates of opioid use disorder and opioid overdose deaths in this vulnerable population.