I enjoy the challenge of the diagnostic process of medicine, which is one of the many reasons I have chosen to work as a nocturnist, which is a hospital-based physician who works overnight. In my free time, I've been known to read books about the American Revolution and Colonial Period, or attend hard rock/metal concerts. Also, '90s music is in my head all of the time. 

I am originally from Cambridge, Massachusetts. I practiced in Quincy for 30 years before coming to South Shore Medical Center in 2002. I am experienced in abdominal surgery, trauma, and management of skin and soft tissue tumors. 

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.

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 a physician is an honor and a privilege I have enjoyed since graduating from The Johns Hopkins University School of Medicine in 1979.  As my patients know I am interested in your life, your passions and the Orthopaedic issues that frustrate you and how I might be of assistance to you.  Surgery is not always a solution.

I take care of newborn infants and their great grandmothers.  In an era of sub-specialization, I am the "silver haired" General Orthopaedist but have maintained my surgical skills and remain confident in my abilities.  I have been fortunate to have treated multiple generations of my friends and neighbors here on the South Shore and work in a hospital committed to clinical excellence and compassionate care.