Peter Greenspan, MD is an Assistant Professor of Pediatrics at Harvard Medical School, and holds the rank of Pediatrician at Massachusetts General Hospital. He is the Vice Chair, Department of Pediatrics, Massachusetts General Hospital and the Medical Director of the MassGeneral Hospital for Children. He is also a practicing pediatrician at Mass General West in Waltham, MA. He is the Pediatric Medical Officer in the H1N1 planning effort. He graduated from Boston University School of Medicine in 1976 and did his Pediatric residency training at Massacusetts General Hospital. He has published on the topic of regional variations in pediatric hospital admissions.