Rates of opioid use disorder (OUD) have increased in older adults (age ≥ 50). Medications for OUD (MOUD) treat OUD effectively; however, limited data exist on whether older adults with OUD are provided MOUD. Using 2016-2020 claims data from Medicare beneficiaries with a new episode of OUD, we calculated rates of MOUD initiation (first dispensing within 14 days of index event), engagement (dispensing of a second MOUD within 34 days of initiation), and retention (receiving MOUD consistently over 180 days). Among beneficiaries with qualifying index events (N = 40 336), 17%, 38%, and 45% were ages 20-49, 50-64, and ≥ 65, respectively. Five hundred and three beneficiaries with a qualifying index event (1.3%) initiated MOUD, 461 (1.1%) reached engagement, and 309 (0.8%) were retained. Multivariable logistic regressions showed older age was associated with reduced MOUD initiation (compared with those aged 20-49, adjusted odds ratios [aORs] were 0.79 [95% CI, 0.64-0.98] and 0.36 [95% CI, 0.25-0.51] for ages 50-64 and ≥65, respectively). Reduced MOUD initiation was associated with female sex (aOR = 0.74; 95% CI, 0.61-0.89) and increasing comorbidity score (aOR = 0.76 per 1-point increase; 95% CI, 0.72-0.80). These results suggest that in addition to general efforts to increase uptake of MOUD, age-specific strategies are needed.