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.

Prior to joining Cohasset Pediatrics I practiced pediatrics south of Boston for nine years and was Chief of Pediatrics for four years within that practice.  

I received my undergraduate degree in Drama from New York University’s Tisch School of Arts.  Working as an actress afforded me the opportunity to travel professionally and experience life as a performing artist in New York City, Los Angeles and London. While working in show business was certainly exciting, I found my true calling working as a physician partnering with parents to help provide the best medical care for their children.

When not at work, I love spending time with my husband and two children and enjoy singing when I get the chance.

My goal as an FNP is to create a safe and welcoming environment where patients can openly share their concerns and trust that I’ll provide the best possible care. 

I always strive to better my practice to have the opportunity to make a difference in my patients' lives. I want to be the provider that patients come to, knowing they will feel heard; and empowering them to take control of their overall wellbeing. I believe in the importance of going above and beyond for each individual patient to optimize their quality of life. Outside of work, I enjoy traveling and hiking with my wife and dog!