Dr. Thomas Gill is Professor of Medicine, Epidemiology, and Investigative Medicine and the Humana Foundation Professor of Geriatric Medicine at Yale University. He is a graduate of the Pritzker School of Medicine at the University of Chicago, and he completed his residency training in internal medicine at the University of Washington. Dr. Gill received his research training in clinical epidemiology as a Robert Wood Johnson Clinical Scholar at Yale, and he joined the Yale faculty in 1994 after completing an additional year as a geriatrics fellow. Dr. Gill is a leading authority on the epidemiology and prevention of disability and functional decline among older persons. His findings have been published in high impact biomedical and epidemiology journals, including the New England Journal of Medicine, JAMA, Annals of Internal Medicine, and American Journal of Epidemiology. Using data from his unique and highly innovative longitudinal study, Dr. Gill has provided compelling evidence to support an emerging paradigm of disability as a reversible, and often recurrent, event, more similar to falls and delirium than to progressive disorders such as Alzheimer’s disease. He has shown that disability often occurs insidiously, particularly among older persons who are physically frail, and that illnesses and injuries leading to either hospitalization or restricted activity, particularly falls and fall-related injuries, represent important sources of disability, regardless of the presence of physical frailty. Informed by the results from his epidemiologic studies, Gill successfully implemented a landmark clinical trial, which demonstrated that functional decline among frail elderly persons can be prevented. Finally, he has also authored numerous other reports on the home environment, bathing disability, and measurement issues that have vexed the field.