Medicaid: Increased Patient Access To MOUD In Residential Treatment Associated With Facility Openings And Closures, 2012-22.

Starting in 2015, states could access previously restricted Medicaid funds for residential addiction treatment through Medicaid Section 1115 waivers, contingent on new requirements. Using facility-level survey data and a quasi-experimental difference-in-differences framework, we describe changes in Medicaid patients' access to medications for opioid use disorder (MOUD) in residential addiction treatment facilities during the period 2012-22 and assess the role of facility turnover in these outcomes. Four years after the policy took effect, facilities in six intervention states that adopted the waivers were 26 percentage points more likely to accept Medicaid patients and provide MOUD relative to nineteen control states. Most of the increase (89 percent) was driven by differences in facility entry and exit. Intervention states experienced significant facility turnover in the residential treatment market after the policy was implemented; entrants were more likely to have MOUD available for Medicaid beneficiaries, whereas facilities that did not provide MOUD were more likely to exit. Among continuously operating facilities, Medicaid participation improved, but MOUD availability did not. These findings highlight the fact that provider entry and exit have the potential to accelerate policy effects.