State Medicaid Policies Governing Access to Medications for Opioid Use Disorder (MOUD) and MOUD Treatment Use in a Large Sample of People Who Inject Drugs in 20 U.S. States

Background: People who inject drugs (PWID) are especially vulnerable to harms from opioid use disorder (OUD). Medications for OUD (MOUD) effectively reduce overdose and infectious disease transmission risks. Objective: We investigate whether state Medicaid coverage for methadone and buprenorphine is related to past-year MOUD use among PWID using cross-sectional, multilevel analyses with individual-level data on PWID from the Centers for Disease Control and Prevention’s 2018 National HIV Behavioral Surveillance. The sample included 8,142 PWID aged 18-64 who reported daily opioid use from 22 U.S. metropolitan areas. Our outcome was any self-reported MOUD use in the past 12 months. Exposures were state Medicaid coverage and prior authorization requirements for methadone and buprenorphine. We interacted these exposures with PWID race/ethnicity, insurance status, and spatial access to treatment and harm reduction resources. Results: Compared with PWID in states without Medicaid methadone coverage, odds of past-year MOUD use were 73% (pp