This is the first submission of this application for competitive renewal of the fourth cycle of the Adolescent Health Promotion Research Training Program at the Johns Hopkins School of Medicine. The goal of the program is to provide training in sexual and reproductive health (SRH) research to post-doctoral Adolescent Medicine physicians. While there has been some major success in utilizing effective interventions to address the high rates of SRH morbidity among adolescents and young adults (AYA), significant age- and racial-ethnic health disparities exist for youth in the United States. This is compounded by workforce shortages of individuals who are trained in Adolescent Health with specialized skills to use scientific evidence to ensure the healthy transition of youth into adulthood. Adolescent Medicine specialists, physicians who have contact with AYA in clinical settings, must also serve as leaders in the development and implementation of new prevention strategies to effectively prevent STIs, HIV, and unplanned pregnancy. This requires physicians to critically understand the biopsychosocial development of adolescents and to build upon scientific advancements derived through collaboration with nurses, psychologists, epidemiologists, behavioral, social, and basic scientists, and statisticians. We have created an interactive, interdisciplinary, team-science training environment using an adult learning model that facilitates effective engagement of physicians and research scientists across pertinent disciplines to foster the development of our trainees. Over the last decade, we have successfully recruited and retained a diverse pool of fellows, most of whom are women and half are from under-represented minority groups. Of the fellows appointed to the grant in the last cycle, 100% completed advanced graduate coursework at the Bloomberg School of Public Health and 80% entered the program with or formally obtained advanced degrees, all fellow graduates who attempted subspecialty certification boards have been successful, all graduates were employed in a related field at fellowship completion, and two recently received NIH K23 mentored awards. Based on these successes, we now request an additional five years of funding to continue to support three fellows per year. The Adolescent Health Promotion Training program at Johns Hopkins University is uniquely qualified to develop and maintain such a program given the active research programs in our unit, the quality of our core faculty, the successful outcomes of our previous trainees, the infrastructure, resources, and environment available to foster research development, and the continuous influx of bright dedicated physicians committed to careers in Adolescent Medicine. Our program also emphasizes innovation at the intersection of SRH and the social ecology of adolescence to reduce health disparities in line with national health objectives.