Bruce Leff, MD, is Professor of Medicine at the Johns Hopkins University School of Medicine. He holds a Joint Appointment in the Department of Community and Public Health at the Johns Hopkins School of Nursing and the Department of Health Policy and Management at the Johns Hopkins University Bloomberg School of Public Health where he is also a member of the Health Services Research and Development Center and the Lipitz Center for Integrated Health Care. He is the Director of the Center on Aging and Health (COAH) Program in Geriatric Health Services Research and the Co-Director of the Elder House Call Program, in the Division of Geriatric Medicine at the Johns Hopkins University School of Medicine. His principal areas of research relate to: the development, evaluation, and dissemination of innovative models of care for older adults, notably the Hospital at Home model of care, as well as Guided Care and home-based primary care. In addition, his research interests extend to issues related to the care of people with multiple chronic condition, guideline development, quality measures for patients care for in home-based primary care, and case-mix issues. He is a member of the Johns Hopkins ACG Case-Mix system team. He has developed national curricula to train physicians in the development of medical homes. Dr. Leff cares for patients in the acute, ambulatory, and home settings. He directs the Medicine Clerkship at the Johns Hopkins University School of Medicine and has received awards for his teaching and mentorship. He is a member of the Board of Regents of the American College of Physicians, Past-President of the American Academy of Home Care Physicians, and is an Associate Fellow of InterRAI.