Project Summary The Pediatric Scientist Development Program (PSDP) remains committed to building a diverse next generation of pediatrician scientist leaders, including: (a) to recruit diverse pediatric fellows whose outstanding potential for a successful investigative career can be developed in an intensively mentored setting and (b) to expand and diversify the pipeline of superbly trained pediatric physician-scientists, who will catalyze cutting-edge discoveries in child health and lead the pediatric departments of the future. Despite the successful history of this program, the ongoing limited diversity of pediatrician scientist leaders and the changing landscape of health care, academic medicine, and biomedical research requires ongoing modifications. The innovative aspects of this resubmission include: 1. Sustain our diversity recruitment pipeline that includes a successful re-focus of the AMSPDC Frontiers in Science (FIS) resident research experience as a diverse candidate pool and partnership with organizations that train diverse academic pediatricians, to maintain a goal of ≥25% of applicants and >50% scholars from underrepresented in medicine (URiM) backgrounds in this grant cycle 2. Harness the power of our robust, alumni network for near-peer mentoring and pipeline enhancement 3. Co-sponsorship of fellows by foundations focused on child health research for general pediatric and disease-specific research training 4. Partnerships with complimentary training programs to aid PSDP fellow interdisciplinary training and networking 5. Added flexibility for the clinical training component to focus on the disease area of research, building the desired synergy in research and clinical training 6. New funding strategy that will support applicant pool flexibility and the fellow-to-faculty transition 7. Iteratively informed hybrid curriculum with “flipped classroom” interactive components, and a focus on diversity and health equity aspects of pediatric research 8. Virtual platforms to enhance recruitment, selection, and professional development delivery We project to train 55 PSDP Scholars in subspecialty fellowships (2023-2028). Of the 55 Scholars, 32 Scholars will be funded by the NIH (includes one slot for HIV-related work co-funded by the Office of AIDS Research). We will also have one intramural slot funded by the NICHD Division of Intramural Research. The PSDP will build on lessons of more than 39 years to strengthen our national network, evolve career development emphases and novel educational approaches, diversify the pediatric research workforce pipeline, and nurture the next generation of diverse pediatric physician-scientists who will generate innovations children's health.