Residential treatment and medication treatment for opioid use disorder: The role of state Medicaid innovations in advancing the field.

Background: Mortality due to opioid use continues to increase; effective strategies to improve access to treatment for opioid use disorder (OUD) are needed. While OUD medications exist, they are used infrequently and often not available in residential addiction treatment settings. CMS provides expanded opportunities for Medicaid reimbursement of treatment in residential facilities and requires states that request Medicaid SUD Waivers to provide a full continuum of care including medication treatment. The objective of this study was to assess how states facilitate access to OUD medications in residential settings and whether Medicaid requirements play a role. Methods: Using a legal mapping framework, across the 50 states and DC, we abstracted data from state regulations in 2019 - 2020 and Medicaid Section 1115(a) demonstration applications. We examined the temporal relationship between state regulations regarding medication-assisted treatment for OUD in residential settings and Section 1115(a) demonstrations. Results: We identified variation in regulations regarding medication treatment for OUD in residential settings and possible spillover effects of the CMS requirements for Medicaid SUD Waivers. In 18 states with relevant regulations, regulatory approaches include identifying opioid medication treatment as a right, requiring access to OUD medication treatment, and establishing other requirements. 25 of 30 states with approved Section 1115(a) demonstrations included explicit requirements for OUD medication treatment access. Four states updated OUD medication treatment regulations for residential treatment settings within a year of applying for a Section 1115(a) demonstration. Conclusions: State regulations and Medicaid program requirements are policy levers to facilitate OUD medication treatment access.