In 2011, almost 26 million Americans suffer from diabetes, making it one of our most costly diseases in human and economic terms. To cure and prevent diabetes will require development of a corps of dedicated young diabetes researchers who have received multi-disciplinary training. The Joslin Diabetes Center T32 Training Program in Diabetes and Metabolism aims to attract outstanding young scientists into research on diabetes and metabolism, and train them in a vibrant and collaborative environment in which they are exposed to the many facets of diabetes and its causes. The Joslin Diabetes Center, founded in 1898, is a collaborative and integrated organization that fosters cutting-edge research and outstanding diabetes care, and incorporates a strong research base and a busy clinic in a single facility. Its physical and academic infrastructure is greatly enhanced by Joslin having been supported as a Diabetes and Endocrine Research Center (DRC) since 1986. The rich training environment of this T32 Program derives not only from Joslin itself, but also from the many close ties and collaborations that Joslin has with Harvard Medical School and many of its affiliated hospitals. In its 35 years of existence this T32 Program has trained many outstanding diabetes researchers, including five members of the current T32 Program Faculty. Our former postdoctoral trainees from the last 10 years have been awarded numerous federal grants (including R01, K99/R00, K08, and F32 awards), and include 12 Assistant or Associate Professors, most of whom are appointed at medical schools. Our pre- and post- doctoral trainees from this time have published many papers in the highest-caliber basic and clinical journals. This application aims to continue and build upon this excellence in training. Since the end of 2008 this T32 program has been directed by T. Keith Blackwell, MD, PhD, an Associate Research Director at Joslin. He is supported by an Executive Committee and an Education Coordinator, and the Joslin Fellowship Selection Committee. The Joslin T32 Program Faculty covers a wide range of interests encompassing Types 1 and 2 diabetes, metabolism, and diabetic complications, and includes basic, clinical, and translational scientists. This applicatio requests support for the same number of training positions as in the last grant period: five postdoctoral slots, two dedicated Pediatric postdoctoral slots, three predoctoral slots, and two short-term slots for summer research. As currently, a mix of MD, MD/PhD, and PhD trainees will be selected from Joslin research groups, endocrinology training programs at Harvard-affiliated hospitals, Harvard PhD programs, and other sources. The proposed Program Plan includes new initiatives for trainee recruitment and education that have been put in place by Dr. Blackwell, including opening the predoctoral program to Joslin/DRC-affiliated labs at nearby Harvard affiliates. These initiatives are designed to strengthen further our trainee base and the training that we offer, bring top young scientists into diabetes research, and foster collaborations among our trainees, Joslin research groups, and other Harvard-affiliated diabetes and metabolism researchers.