I am the Medical Director of Population Health for South Shore Health and divide my time between administration and patient care. My administrative interests include integration of care, professional development, and community centered program development. I value long-term relationships with my patients and find it a privilege to care for patients over their lifespan.

I was drawn to family medicine because joining patients on their journeys to healthier, happier lifestyles is incredibly rewarding. I strive to always provide care that is patient-centered and evidence-based in both primary care and the hospital. Outside of medicine, I love traveling and enjoying new restaurants with my wife.

A hospitalization is often wrought with difficult news and decisions; it is my honor to care for patients at these times. I enjoy working with a care team, to deliver high-quality care. Above all, I try to foster sincere relationships with patients, focusing on what is most important to each person.   

William Tollefsen, MD is the EMS and MIH Medical Director for South Shore Health. Dual-boarded in Emergency Medicine and EMS Medicine, Dr. Tollefsen works clinically as an Emergency Physician at South Shore Health in addition to his role as EMS Medical Director.

One of few physicians in the country to receive the prestigious "FAEMS" recognition, Dr. Tollefsen is also the Medical Director for OEMS Region IV, serving 61 cities and towns of the Metro-Boston EMS Council. As the current EMS Medical Director for eight municipal and three private ambulance services on the South Shore, Dr. Tollefsen interacts and provides oversight for over 400 Paramedics.

Dr. Tollefsen graduated from New York Medical College and completed residency training in Emergency Medicine at Harvard University, Brigham and Women's, and Massachusetts General Hospital. He completed a fellowship in Emergency Medical Services and Critical Care Transport at the University of Massachusetts, where he worked as an Emergency Physician and Flight Physician for UMASS LifeFlight. He completed an MBA at the Isenberg School of Management at UMASS Amherst, and holds a Master of Medical Science degree from the Boston University School of Medicine.

A former pre-hospital provider, he is actively involved in EMS system design, paramedic education and Critical Care Transport Systems. He works closely with multiple EMS, Fire and Law Enforcement agencies throughout Massachusetts.

His research interests include systems of care, resuscitation, airway management, and paramedic education.

I am honored to treat and work with my patients. When I am not working, I am running marathons or trails, skiing, biking or cooking. Health and wellness are some of my passions.