PROJECT SUMMARY As the nation continues to grapple with rising alcohol-related hospitalization and mortality, expanding access to alcohol use disorder (AUD) treatment remains an urgent public health priority. While Medicaid is positioned to be a key policy lever to improve access to AUD treatment and reduce mortality among vulnerable populations, many state Medicaid programs do not cover the full continuum of AUD treatment and use utilization management parameters that may restrict access. Moreover, most state Medicaid programs contract with managed care organizations (MCOs). While over 70% of all Medicaid enrollees participate in MCO plans, little is known about how these plans cover AUD treatment. To fill this gap in the scientific evidence, we will conduct the first multi-state study of the effects of Medicaid MCO coverage and utilization management design on AUD treatment receipt and outcomes. The study will encompass 142 MCO plans, across 18 states, for the full continuum of treatment. We also propose to make use of innovative random auto-assignment methods in two state Medicaid programs. Our specific aims will include: (1) estimating how MCO plans’ coverage and utilization management designs are associated with progression through the major stages of identification and treatment of AUD (diagnosis, initiation, engagement, and retention); (2) estimating how MCO plans’ coverage and utilization management parameters are associated with alcohol-related emergency department visits and hospitalizations; and (3) estimating how progression through the stages of identification and treatment of AUD is associated with alcohol-related mortality. The proposed study will be the first comprehensive investigation of the effects of MCO coverage for AUD treatment on treatment receipt and outcomes – evidence without which the care of a large fraction of the AUD population is compromised. As alcohol-related hospitalization and mortality continue to rise, evidence regarding the impact of Medicaid MCO coverage for AUD treatment is urgently needed. This research will equip policymakers with evidence-based guidance on how to structure MCO contractual arrangements to ensure appropriate and efficient access to AUD treatment. 1