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.

My mission is to provide compassionate and effective care to treat patients in critical moments in order to ensure the best possible outcomes through prompt intervention and evidence-based practices.

I completed residency at Boston Medical Center. I believe in providing evidence-based and compassionate care at all times and in honest and open communication with my patients about their condition and treatment. Outside of work, I enjoy rock climbing and spending time outdoors and with my family.

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.

My objective is to help my patients manage and maintain their physical and mental health. 

I truly enjoy working with and helping my patients to be their healthiest versions of themselves. I enjoy the long-term relationships that I have developed. it is important to me to take the time to listen, communicate, and build trust with my patients. 

Outside of work, I enjoy traveling, hiking, reading, lifting weights, and spending time with my friends and family.  

I strive to build a space where patients feel safe to discuss their health concerns and engage in shared decision-making.

Prior to joining South Shore Health, I had the privilege to train at UMass Family Medicine Residency and complete an additional year of fellowship to also care for patients living with HIV/viral hepatitis at the Family Health Center of Worcester.

Outside of work, I love spending time with my family, running, gardening, and camping/hiking.