Project Summary/Abstract – Pilot Projects and Mentoring Core Mentoring and training the next generation of HIV and substance use researchers is key to fulfilling our commitment to ending HIV, and we address this through innovative, evidence-based pedagogical approaches. The Center is equally committed to advancing science by increasing the diversity of ideas, experiences and approaches through the recruitment of investigators from underrepresented backgrounds. The Pilot Projects and Mentoring Core (PPM) will support new and early stage investigators (new/ESI) and other CDUHR investigators to meet emerging and historic challenges to ending the HIV epidemic among people who use drugs (PWUD) and carry out personally-rewarding, high-impact research in substance use and HIV. The aims of the PPM Core will be achieved through an individualized approach that centers upon each participant's strengths, training, and identified needs, in addition to considering those of their mentoring team. To this end, the PPM Core builds upon its well-established pillars of evidence-based training and mentoring which include (1) didactic trainings, (2) pilot projects, (3) interdisciplinary team mentoring, (4) individual development plans, and (5) structured support and diversity, equity, inclusion and belonging (DEIB) training for mentors. In CDUHR-6, the Core incorporates three additional innovative pillars that have recently emerged as critical to a comprehensive, evidence-informed, and effective mentoring program: (1) meaningful community engagement principles, (2) training that focuses on maximizing research impact and (3) integrated positionality-informed approaches to mentoring. Each of these eight pillars addresses specific gaps to equip the next generation of investigators to make important contributions toward preventing HIV infection, morbidity, and mortality among PWUD, in alignment with NIH priorities and the overall scientific and infrastructure aims of the Center. We are committed to supporting our investigators to address complex problems, as represented in the CDUHR-6 theme of “Reinvigorating HIV Prevention and Care for PWUD: Accelerating progress and sustaining gains in the midst of societal disruption.” The PPM Core will leverage the outstanding experience, knowledge, and resources represented within the Center to enable our scientists to strengthen their research skills and develop strong and fruitful collaborations with community members and colleagues to pursue a personally rewarding career in research.