Project Summary/Abstract Advances in basic science and pre-clinical research have significantly increased our understanding of the neurobiological underpinnings of addiction. However, there is a need to train investigators who can move these discoveries from the lab to the clinic. Our T32 fellowship meets this need, by training clinician- scientists dedicated to translational research in substance use disorders (SUDs). This renewal application will continue our postdoctoral program which is specifically designed for physicians and clinical psychologists. The main objective of this program, now in its 29th year, is to provide both the research skills and clinical expertise necessary to design and carry out independent, translational SUD treatment research. Our program has graduated 25 MDs/DOs, 3 MD/PhDs and 5 PhDs in the past 15 years and is currently training 4 MDs and 2 PhDs. Our graduates have obtained K and/or R awards, engage in team-based research, or attain academic teaching or governmental research-related positions. To provide sufficient support to ensure their success, our trainees are given 2 years of training, and a third year is offered to those making excellent progress but who need more time to obtain independent funding. Our well-funded and diverse pool of senior faculty preceptors have extensive track-records in training physicians and psychologists. Further, we have a growing cadre of junior faculty to provide additional support. In this competing application we are requesting 5 years of funding for 6 postdoctoral fellows to be enrolled each year. Our training includes: 1) Didactic coursework, including weekly seminars that provide a comprehensive overview of the SUD field; instruction on rigor and reproducibility and data science; courses in statistics and research methodology; a monthly workshop on emerging issues in addiction; a 2x/month seminar where fellows and faculty present their latest findings or developing projects; a monthly invited speaker’s seminar; and ongoing instruction on the ethical conduct of clinical research; 2) Research apprenticeship where each fellow works under the close supervision of primary and secondary senior mentors as well as a junior/mid-career investigator; 3) Clinical experience in the major modalities used to treat SUDs; and 4) Development of teaching skills where each fellow engages in seminars with medical students and housestaff and present research findings at journal clubs and scientific meetings. While our traditional foci of training remain clinical trials and human behavioral pharmacology, new opportunities such as novel therapeutics, implementation science, and clinical effectiveness research (using electronic health records/big data) are available to our fellows as they choose their own career paths as future clinician-scientists.