The goal of this clinical trial is to learn if receiving peer recovery support (support services provided by trained "peers" with lived experience of addiction and recovery) improves retention in medication treatment among people with opioid use disorder. The main question it aims to answer is: does peer recovery support improve retention in medication treatment for opioid use disorder?

Researchers will compare two groups: (1) standard care combined with a peer recovery support program, and (2) standard care alone, to see if peer recovery support works to improve retention in medication treatment for opioid use disorder.

Participants will: visit clinics as they normally would to receive standard care (medication treatment for opioid use disorder); complete two questionnaires - one when they start treatment and one 6 months later; and agree to let researchers use information from their medical record. Participants in group 1 will also be invited to meet with a peer recovery support specialist for up to 6 months.

Inclusion Criteria:

• Adult ≥ 18 years of age
• Initiated medication for opioid use disorder treatment in past 45 days in a Geisinger outpatient clinic
• Willing and able to give informed consent

Exclusion Criteria:

• Received medication for opioid use disorder treatment at a Geisinger outpatient clinic in the 90-day period prior to the treatment initiation date
• Not proficient in English

A dataset from the randomized controlled trial (RCT) of U.S. adult patients initiating medication for opioid use disorder treatment will be shared. The data will be obtained from electronic health records (EHRs) and two assessments completed by study participants at baseline and 6-months follow-up. Data elements include each patients' study group assignment (standard care (SC) or SC plus the peer recovery support program), study outcomes, demographic and clinical covariates, and potential mediating and moderating variables. A second dataset from the subset of individuals randomized to SC+PRS will be shared. This data will come from a combination of EHRs, study logs, and assessments completed by patients. Data includes variables pertaining to patient's degree of engagement and satisfaction with the PRS program.

Data will be released when study results are published, or at the end of the granting period, whichever comes first. Data will be permanently archived.

De-identified datasets and meta-data will be available to access via the National Addiction & HIV Data Archive Program (NAHDAP) repository. Accessing data will require user registration and agreement to the data repository's terms of use, which require users to make no attempt to identify human subjects, cite the data/DOI, and not redistribute the data without NAHDAP written permission.