This trial tests the Minds and Mentors Program, a group therapy that uses mindfulness and peer support, in people with opioid use disorder who are on medication. The goal is to see if it helps them stick to their medication, reduces relapse rates, and lowers stress and cravings. Mindfulness-based relapse prevention (MBRP) includes the teaching and practice of mindfulness meditation to help patients change their relationship to drug cravings and other negative emotional states.