RESEARCH AND EVALUATION CORE: PROJECT SUMMARY/ABSTRACT Although effective primary prevention, harm reduction, treatment, and recovery support interventions for substance use disorders and pain exist, they are not widely available. Crosscutting dissemination and implementation (D&I) scientific methods are required to select and deliver effective and efficient implementation strategies under variable contexts. The Research Adoption Support Center’s Research and Evaluation (R&E) Core, in concert with the Administrative, Substance Use Disorder Implementation Support (SUD-IS) and Pain Implementation Support (Pain-IS) cores, utilizes an integrated, multidisciplinary, iterative approach to provide rapid assessment, expert technical assistance, and advance the long-term adoption and sustainment of evidence-based interventions. The overarching goal of the R&E Core is to elevate the D&I capability and translational long-term impact of the HD2A Innovation Projects. We achieve this via standardized baseline information and on-demand support for data, analytic, and research translation needs, all toward leveraging sustainable change through science-based financing and policies. We will provide state- of-the art methodological support in D&I measurement, frameworks, modeling, and testing/evaluation, guided by R&E Core experts who have conducted extensive work across the four HHS pillars. Aligned with other RASC cores, we are guided by 3 dynamic phases: 1) ASSESS Innovation Projects’ baseline D&I capacity via 3 methods; 2) ASSIST the Innovation Projects in increasing D&I capability, while supporting harmonized data collection and reporting across projects; and, 3) ADVANCE Innovation Projects’ potential for sustainment and scale-up, and serve as the D&I research methodology resource to the HD2A Modeling and Economic Resource Center (MERC) and Data Infrastructure Support Center (DISC). A key function of the R&E core is the formative evaluation, a phased evaluation that will incorporate lessons learned within and across HD2A grantees, with formative evaluation reports (Years 1, 3) focused on providing insight to support timely decision- making and course corrections by grantees and NIH, and a final report (Year 5) focused on informing future initiatives of this kind. We also will conduct 5 Rapid Turnaround Research Projects designed to produce knowledge to address persistent or emerging barriers to implementation or sustainment identified by HD2A grantees. The Year 1 project will focus on the role of insurance coverage and other financing and reimbursement barriers to the widespread adoption of medications for opioid use disorder (MOUD). Within and beyond the HD2A program, we boldly seek to contribute knowledge and methods to the addiction and pain intervention fields with the ultimate goal of transformational and equitable public health benefit.