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.

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 philosophy is to listen carefully, ask the right questions, and offer my expertise within the scope of my skills.

I was born in New York City to immigrant Latino parents. Yes, I root for the Yankees, of course!

Outside of work, I enjoy physical fitness and spending time with my family. 
 

I have been a physician's assistant in women’s health for close to 30 years on the South Shore. I enjoy seeing women in their many phases of life. I feel privileged when patients I met at the start of my career bring their daughters and granddaughters in to see me for their care. When not working, I enjoy spending time with my family.