This hybrid implementation-effectiveness trial will evaluate Mindfulness-Oriented Recovery Enhancement (MORE) for patients with opioid use disorder receiving methadone treatment (MT). The investigators will also assess barriers and facilitators to integrating MORE into methadone treatment, and evaluate the impact of a sustainable train-the-trainer model on provider burden, intervention fidelity, intervention engagement, and outcomes. Participants will be assigned to a higher intensity MORE implementation strategy, a minimal intensity implementation strategy consisting of a simple, scripted mindfulness practice (SMP) extracted from the MORE treatment manual with minimal training and feedback and no supervision, or methadone treatment as usual (TAU). We aim to: * Examine barriers and facilitators to the implementation of MORE and SMP in MT and evaluate strategies for optimizing training, fidelity, and engagement. * Evaluate the effectiveness and treatment fidelity of a higher intensity MORE implementation strategy versus a lower intensity, scripted mindfulness practice (SMP) implementation strategy as an adjunct to methadone TAU or methadone TAU, only. Outcomes include opioid and other drug use, craving, MT discontinuation, depression, anxiety, and physical pain (secondary outcomes) than patients randomized to TAU.