The Tailored Retention and Engagement for Effective integrated Treatment of OUD and Pain (TREETOP) clinical research center at the University of Pittsburgh (Pitt) is part of the NIH IMPOWR network. TREETOP draws on the NIDA Clinical Trials Network Appalachian (Pennsylvania & West Virginia) and Western States (Oregon) Nodes and the Community-based OUD and Pain Enhanced treatment (COPE) collaborative (Baltimore, Maryland) to develop effective, integrated, and sustainable interventions for chronic pain and OUD. Our overall goal is to improve comprehensive treatment for comorbid chronic pain and OUD, including impacted patients in rural and urban communities. We will achieve our overall goal through the integrated contributions of 5 center components as follows: 1) Research Site Overview, Management, and Operations - Our multidisciplinary team has extensive experience with multisite clinical trials as well as in TREETOP’s emphasis areas of implementation science and comprehensive integrated treatment. 2) Engagement and Outreach - Our TREETOP Stakeholder Consultation Board (SCB) includes patients, community members and policymakers. 3) Engagement/Retention Research Projects - Both projects share the central premise that treating chronic pain improves pain and OUD outcomes. Both randomized controlled trials (RCTs) tailor a pain self-management (PSM) intervention to patients with co-morbid chronic pain and OUD, and evaluate both the intervention’s effectiveness and the barriers and facilitators to effective integrated and sustained implementation of the intervention through established frameworks. Specifically, the Engagement research project investigates whether PSM can improve pain and engage primary care patients in medication treatment for OUD, while the Retention project investigates whether PSM and/or patient-centered buprenorphine dosing can improve pain and retention in treatment among patients who have already initiated care in office-based addiction treatment programs. 4) Data Collection, Management, and Harmonization - The Data Core will be led by investigators with a track record of success in the measurement and analysis of patient-reported outcomes and in leading clinical trials and data coordinating centers, and includes national leaders in the PROMIS Health Organization. 5) Pilot Projects - Our Pilot program includes 3 initial studies on pain measurement, chronic pain/OUD treatment implementation in specialty settings, and chronic pain and community-based barriers to services. Overall Impact: Our TREETOP investigators and SCB will collaborate to advance the science of sustainably and effective integrated treatment for chronic pain and OUD.