My mission is to care for all patients wisely, fairly, and with respect.  

I work hard to provide the best emergency care to the greatest number of patients, and to treat every patient with the respect and importance that they deserve.

I grew up in Scituate and am a proud graduate of Scituate High School.  After graduating from Harvard-Radcliffe, I continued doing another year of diabetes research at Massachusetts General Hospital, then did two years of breast cancer research at the Dana-Farber Cancer Institute.  I graduated from the Boston University School of Medicine, went to UMass Worcester for residency, graduated from the Harvard School of Public Health, and then went to Brown for residency.  I began working at South Shore Medical Center in 2008.  I especially enjoy seeing patients who knew my father, a police officer in Scituate for 29 years and hearing their stories about him.  I try to motivate, encourage and work with my patients and it is an honor and a privilege to be able to care for them.  Outside of work, I love dancing, playing frisbee, and spending time with my family. 

Communication is the single most important tool in medicine which I try to achieve every day.

In my free time I enjoy cooking, spending time outdoors, and being with friends and 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.

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 culturally competent, evidence-based, and compassionate care to improve the quality of life of all of my patients. 

Medical care that not only tends to patients’ physiological ailments but imparts a sense of emotional comfort is the preeminent force in my practice. I completed my training at Tufts University School of Medicine, where I received a Masters Degree in Medical Science and another Masters Degree in Public Health.