UCSF is one of six sites across the country in a new NIDA Clinical Trials Network randomized effectiveness-implementation trial. The study objective is to determine whether office-based methadone with pharmacy administration/dispensing or buprenorphine (BUP) results in greater treatment retention in patients with opioid use disorder (OUD). The study also will identify implementation barriers, facilitators and acceptability at the patient, provider, and health-systems level for office-based methadone with pharmacy administration and/or dispensing. The study in San Francisco is conducted at the Outpatient Buprenorphine Induction Clinic (OBIC) in the SOMA neighborhood and will enroll at least 100 patients over a 3-year study period.This position supports the Principal I