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.

My mission is to provide excellent care to all of those in need with compassion and empathy.

I grew up in Duxbury, MA on the South Shore and attended Colby College in Maine. I then obtained my Master of Science degree at Mercer University School of Medicine in Georgia. After securing those credentials I attended MGH Institute of Health Professions for PA school, where I graduated in 2021. I take pride in getting to know each patient, their specific medical condition and then guiding them through difficult medical pathways and stressful circumstances. I enjoy my work/life balance and love traveling, workout classes, skiing, and everything wellness.

My mission is to provide safe, high quality, patient centered care in collaboration with the patient, their family, and other providers on the care team to promote the patient’s goals of care and overall well-being.

It is a privilege to advance my role as a nurse anesthetist at South Shore Hospital. It is of utmost importance to me that I gain the trust of my patients and involve them in the plan of care with effective communication and transparency. Being an advocate for my patients during the perioperative period is my priority. When I am not at work, I enjoy gardening, hiking, spending time at the beach, and cooking.