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.

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.

As the Medical Director of Addiction Medicine at South Shore Health, I work to tackle the defining medical challenge of our time: Substance use and alcohol use disorder.

In addition to seeing adult patients at South Shore Hospital, I work with colleagues across South Shore Health to develop and implement a comprehensive addiction medicine treatment program. This program will connect patients with the resources they need to manage substance use disorder, no matter if they come to us through the Emergency Department, primary care, or another setting. Additionally, I serve as Medical Director for Spectrum Health System's opioid treatment program, ATS/detox, CSS, and therapeutic community in Weymouth.

Prior to my work at South Shore Health, I helped launch the Bridge Clinic at Boston Medical Center, which connected patients with treatment options for substance use disorder. I also served as Medical Director for Spectrum Health Systems’ Opioid Treatment Program in Weymouth.

In my spare time, I enjoy baseball, reading fiction, snowboarding, and cooking.

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. 

I strive to educate patients about their health conditions in order to best include them as part of the treatment team.

Brendan has spent a large portion of his career practicing in Primary Care following graduation from MCPHS University in 2014.  Having grown up in Massachusetts, as well as living and working in Southeastern Mass he has formed close relationships with his patients as they are frequently his neighbors, mechanics, former teachers and the like. From these relationships, he has learned the importance of community as part of a medical treatment plan, and this has now become an important aspect to the way he practices medicine. He is very excited to extend his medical career into the South Shore Health Community. 

Having sustained a major trauma or having undergone any kind of surgery (major or minor) can be extremely stressful. I often find myself treating patients and talking with families when they are often feeling at their worst. This is the time when I feel my warm personality and compassion can be the biggest contributors to alleviating some of that stress and anxiety. Outside of my practice, I prefer to spend time with my family enjoying the splendors of the South Shore.