Key PointsQuestionDid rates of methadone dispensing for opioid use disorder increase after Medicare payment and COVID-19 policy changes in 2020, and did these rates vary by beneficiary age and dual eligibility for Medicaid?FindingsIn this cross-sectional study of 9 870 791 Medicare Advantage enrollees, increased rates of methadone dispensing were observed, largely driven by beneficiaries dually eligible for Medicare and Medicaid and those younger than 65 years.MeaningThese findings suggest that policies designed to increase access to methadone treatment appear to have increased access to medication treatment for Medicare beneficiaries with opioid use disorder, helping to meet national policy priorities.