RESUMO
INTRODUCTION: People experiencing homelessness (PEH) bear disproportionate opioid mortality. This article aims to determine how state Medicaid expansion under the Affordable Care Act impacted the inclusion of medications for opioid use disorder (MOUD) in treatment plans for housed versus homeless individuals. METHODS: The Treatment Episodes Data Set (TEDS) provided data on 6,878,044 U.S. treatment admissions between 2006 and 2019. Difference-in-differences analysis compared MOUD treatment plans and Medicaid enrollment for housed versus homeless clients in states that did and did not expand Medicaid. RESULTS: Medicaid expansion was associated with a 35.2 (95 % CI, 11.9 to 58.4) percentage point increase in Medicaid enrollment and an 8.51 (95 % CI, 1.13 to 15.9) percentage point increase in MOUD-inclusive treatment plans for housed and homeless clients alike. Yet the pre-existing MOUD disparity persisted, with PEH being 11.8 (95 % CI, -18.6 to -5.07) percentage points less likely to have MOUD-inclusive treatment plans. CONCLUSIONS: Medicaid expansion may be an effective tool for increasing MOUD treatment plans for PEH in the 11 states that have not yet implemented the policy, but additional efforts to increase MOUD initiation for PEH will be necessary for closing their treatment gap.