I enjoy taking care of my patients and including their families and the entire treatment team in the process. 

My mission is to provide compassionate care for patients in challenging times.

It is a privilege and an honor to stand alongside patients and their families during some of the most difficult times they may face. I strive to provide thoughtful, effective, and compassionate care while maintaining clear and honest communication throughout the treatment and recovery process in the ICU. So you can get to know me, some of my hobbies include Dodgers baseball, music, gaming, and exercise. I also enjoy traveling around the world with my lovely wife.

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.

Being trusted as a physician to treat patients', sometimes life threatening, medical conditions is a privilege and responsibility I thrive to honor every day. Helping hospitalized patients and their families to cope with changes during these stressful times is crucial to achieve better medical outcomes and to improve the well-being of the community as a whole. 

Outside of work, I like to watch soccer, Crossfit training, travel the world and take photographs. 

I grew up on the South Shore and attended Holy Cross for college where my concentration was pre-medical sciences and sleep research. During summers in college I worked as an EMT and following college I worked in a collaborative Brigham and Women’s Hospital/Harvard Medical School lab studying allergy and asthma. While at the University of Massachusetts Medical School and Lahey Clinic my focus was on primary care internal medicine. In 2006 I was the recipient of the “Patient Care Award” which is Lahey Clinic’s highest physician honor. I joined South Shore Medical Center in 2006.