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.

As a medical student, I was unsure what my clinical focus would be. Once I saw my first delivery, it was clear that this was my future. I started my internship and residency training here in Boston. After moving to California and spending several years practicing there, I knew I wanted to return to Massachusetts. I have been at South Shore Hospital for nearly ten years now and am grateful to work with the women of the South Shore. After many years practicing both Obstetrics and Gynecology, I realized my true love was the Birthing Unit and transitioned to a Laborist position. I am privileged every day to be part of something so amazing and love that I get to share in such an important family experience.

My treatment philosophy and ultimate goal is to collaborate with families to achieve the best birth experience while helping to ensure the wellbeing of mom and baby.

My goal is to establish open communication with patients so we can work together on taking ownership of their health and wellness.

I enjoy the meaningful relationships I have built and the inspiration I draw from patients every day in clinic. A healthy dialogue is an important part of the provider-patient relationship. Outside of work, I enjoy spending time with my family, writing, and staying active outdoors.

It has been my privilege to practice medicine and to have made a difference in the lives of my patients over the past 21 years. I enjoy the challenges of practicing internal medicine in a hospital setting and working as part of a team with our excellent hospitalist providers, consultants, nursing and ancillary staff. I served as Medical Director of the Hospitalist Department from 2009-2015 and am proud to say that we have an amazing program with dedicated clinicians who genuinely enjoy the care of hospitalized patients and are committed to excellence in their every day work. I enjoy giving back by participating in the Pan Mass Challenge which raises critical funds for cancer research and the Multiple Sclerosis cycling events. I enjoy boating, hiking and camping, and long distance bicycling and, most importantly, spending time with my family.

I grew up in a small town in Northern New York, and joined South Shore Hospital and Brigham and Women's Hospital in 2012. I completed my undergraduate and medical education as well as my general surgical training and surgical critical care fellowship at the University of Rochester in Rochester, NY. I am also fellowship trained in minimally invasive and bariatric surgery from Dartmouth Hitchcock Medical Center. I have had a long-standing passion in bariatric and weight-loss surgery and my goal in joining the South Shore Hospital team was to bring that expertise and opportunity to the South Shore community. The hospital has been very supportive in this endeavor and over the past few years we have created a collaborative team of providers from across institutions to start the South Shore Hospital Center for Metabolic and Bariatric Surgery. As medical director it has been my pleasure to help the program grow into a strong clinical component  of the department of surgery and create more outreach into the community. I am also actively engaged as a trauma surgeon and have a busy general surgery practice taking care of a variety of disease processes including the minimally invasive management of gallbladder disease, hernia, GERD, hiatal hernias, as well as the surgical management of a variety of other gastrointestinal disorders. When I am not working, I enjoy the simple things in life like relaxing by a large campfire or spending the day at the beach with my family. 

My goal is to work collaboratively with patients and their families as well as the entire care team to support critically ill patients. Clinical care and working with the entire medical team to support patients and their families are my primary passions. I am also involved in ongoing research using imaging studies to better diagnose, monitor and understand lung disease and critical illness. Outside of work, I am an avid runner and sailor, and love spending time with my family.