The root of the word “doctor” originated from the latin word docere, which means to teach. My philosophy as a doctor is to teach and educate my patients on their conditions and general health.

I love to learn and, therefore, I chose being a doctor as my profession. Being a physician means a life time of learning about diseases and medicine, but more importantly, I get to learn the story behind each of my patients.

Outside of work, I love to learn to sail, and flying. I am also an avid rock climber, hiker, and traveler.

I received my undergraduate degree from Harvard University. I completed my medical degree at the Robert Wood Johnson Medical School in Camden, NJ. My surgical and urological residency took place at the State University of New York Health Science Center in Brooklyn, NY. I am certified with the American Board of Urology and am passionate about providing high quality patient care in a compassionate environment.

I enjoy getting to know patients and treating the whole person. I focus on preventative care and supporting patients to reach their health goals.   

The doctor-patient relationship is at the center of your health care, and I strive to provide care that is collaborative and inclusive. I have a holistic approach, working with patients to treat the cause of medical problems, and reducing prescription medicines when it is safe to do so.   I am also pro-active, coordinating care and advocating for patients as they navigate the health care system. I enjoy caring for newborns, children, and family members of all ages, as well as helping with stress management and healthy lifestyle changes. 

When not working, I enjoy spending time with my family and my extra-large dog, reading, running, cooking, and playing flute, piano and guitar.  

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.