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 have been privileged to provide primary care to patients for 25 years. I started my career in women’s health, then transferred to Affiliated Medical Groups in Quincy. This practice then transitioned to cardiologist Dr. Lisa Antonelli, where I continued my role in providing comprehensive medical care for primary care patients. This practice then joined Dr. Barry Miller’s oncology practice in Quincy, where I continued with my role providing primary care to the adult population. 

In 2008, I decided to join the medical team at South Shore Medical Center, again as a Nurse Practitioner in the primary care role. I feel that I have been fortunate to provide care for many of my very first patients and their families today. 

Outside of work, I enjoy spending time with my two sons and their families. I also enjoy hiking, kayaking, watercolor painting, and traveling.