From Access to Action: Behavioral Economics-Informed Implementation of Integrated HIV and SUD Care - This K24 Midcareer Investigator Award in Patient-Oriented Research (POR) will provide protected time for Oluwaseun Falade-Nwulia, MBBS, MPH, Associate Professor of Infectious Diseases at Johns Hopkins University, to expand a structured, sustainable mentoring program for trainees and early-stage investigators committed to improving health outcomes for people who use drugs (PWUD). Dr. Falade-Nwulia is a clinicianscientist with expertise in infectious disease and addiction care whose research applies implementation science to identify determinants of care engagement and to design, implement, and evaluate strategies that increase uptake of evidence-based interventions; including HIV pre-exposure prophylaxis (PrEP), antiretroviral therapy (ART), direct-acting antivirals (DAAs) for hepatitis C virus (HCV), and medications for opioid use disorder (MOUD). Her mentoring portfolio focuses on investigators whose work addresses the intersecting epidemics of HIV, HCV, substance use disorders (SUD), and overdose among PWUD. Through this K24, Dr. Falade-Nwulia will expand mentoring in POR that integrates behavioral economics, implementation science, and economic evaluation to improve uptake and continuity of care within integrated HIV and SUD care models. Mentoring activities will include longitudinal career development planning, structured works-in-progress sessions, and collaborative research engagement. The mentoring aims are: (1) to develop the next generation of independent physician-scientists and health services researchers equipped to conduct rigorous POR focused on PWUD, and (2) to establish the Nudging Integrated Care and Engagement (NICE) Program, a structured mentoring platform that leverages the robust research and training infrastructure of the Johns Hopkins University School of Medicine and the Bloomberg School of Public Health. The K24-supported research platform will advance the field by: (1) integrating behavioral-economics-informed implementation strategies (e.g., defaults, friction-reduction, incentives, commitment devices, and socialinfluence approaches) into existing service delivery models to address behavioral drivers of under-utilization of HIV prevention and SUD treatment among PWUD; and (2) conducting rigorous mixed-methods and costeffectiveness evaluations to generate scalable, policy-relevant strategies. This award will also allow Dr. Falade-Nwulia to obtain advanced training in behavioral economics and economic evaluation, further enhancing her POR program and capacity to mentor early-stage investigators. Ultimately, this K24 award will accelerate the development of a skilled workforce focused on improving HIV and SUD outcomes among PWUD, while advancing implementation science to optimize integrated care delivery in community-based and rural settings in Maryland and beyond.