Dr. Leff is Professor of Medicine at the Johns Hopkins University School of Medicine. His research focuses on novel models of care delivery for older adults with an emphasis on home and community-based models of care, issues related to multi-morbidity and serious illness, risk prediction, and quality measurement and improvement. He Co-leads the HaH Users Group and the National Home-Based Primary Care Learning Network. He is Founding Executive Editor of the Journal of Advanced Home Medicine, past -President of the American Academy of Home Care Medicine, and currently serves as a Trustee of the ABIM Foundation.
