I strive to help patients attain the best health possible; have full understanding of their health issues; and equip them to take partnership in managing their health.

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.

I grew up in southern Maine and attended Harvard University for my undergraduate education. While at Tufts University School of Medicine and Mount Auburn Hospital in Cambridge, my focus was on primary care medicine. I believe in the dignity of each of my patients. Respect, compassion, and reliability are among my goals in patient care. In my free time, I enjoy the outdoors and the arts, usually in the company of my family. 

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.

I graduated from Colegio Nacional de San Isidro in Buenos Aires, Argentina and completed my medical degree at Buenos Aires University School of Medicine. My surgical and urological residency were spent at the Hospital Italiano in Buenos Aires. I was an attending Urologist at Hospital Roffo in Buenos Aires until I came to the United States. At that point I was a Urology Fellow working on a research project at the Children’s Hospital and Harvard Medical School in Boston. I completed his American residencies in urology and surgery at the University of Massachusetts.

I enjoy spending time with my wife and three children.

My treatment philosophy is to establish good rapport with patients during their difficult moments, and to focus on shared decision-making while working on treatment plans and management of acute issues.

I have been practicing medicine for more than 20 years now. I like communicating with patients while focusing on their medical issues and helping formulate plans to meet the treatment needs. Apart from medicine, I enjoy spending time with my two boys, cooking and baking. I am an avid nature lover and enjoy hiking. Exploring new places brings me true happiness. Yoga and meditation helps me unwind after hectic days. 

My mission is to treat my patients with compassion and kindness and take the time to know and understand them.

I am certified by the American Board of Internal Medicine in Internal Medicine, Medical Oncology and Hematology. I received my BA in Biology at State University of New York at Buffalo and my MD from Jefferson Medical College of Thomas Jefferson University in Philadelphia, PA. I did my residency in Medicine at Lankenau Hospital in Philadelphia, PA and Fellowship in Hematology-Oncology at University of Connecticut Health Center in Farmington, CT. I was recognized in Boston Magazine's 2017 Top Doctors list. Outside of work, I enjoy listening to classical music, traveling, running, and bicycling. 

I try to have a collaborative approach to disease management and prevention, with an eye towards the most value for the patient's dollar.

I have been lucky enough to be a family physician since 2010. Since then, I have worked to provide cost-effective and compassionate care for my patients. I'm also committed to advocacy for my patients and fellow MD's outside the office, though my role on the Massachusetts Academy of Family Physicians. I enjoy traveling, hiking, gardening, and computer gaming, when my young children allow any of them.

I have been a proud member of the Hospitalist group at South Shore Hospital since its inception in 2000. I believe that patients can benefit from a dedicated group of hospital physicians who work in conjunction with the primary care physicians and specialists in the community.  

Outside of work, I enjoy most sports and outdoor life with my family on a small farm in Southern New Hampshire.