Medicaid coverage for methadone maintenance and use of opioid agonist therapy in specialty addiction treatment

Objective: This study examined differences in opioid agonist therapy (OAT) utilization among Medicaidenrolled adults receiving public-sector opioid use disorder treatment in states with Medicaid coverage of methadone maintenance, states with block grant funding only, and states without public coverage of methadone. Methods: Person-level treatment admission data, which included information on reason for treatment and use of OAT from 36 states were linked to state-level Medicaid policies collected in a 50-state survey. Probabilities of OAT use among Medicaid enrollees in opioid addiction treatment were calculated, with adjustment for demographic characteristics and patterns of substance use. Results: In adjusted analysis, 45.0% of Medicaid-enrolled individuals in opioid addiction treatment in states with Medicaid coverage for methadone maintenance used OAT, compared with 30.1% in states with block grant coverage only and 17.0% in states with no coverage. Differences were widest in nonintensive outpatient settings. Conclusions: Medicaid methadone maintenance coverage is critical for encouraging OAT among individuals with opioid use disorders.