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.

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 believe in the prevention of disease and the promotion of healthy lifestyles for all children through education and dedication to quality care.

I like to treat each patient and family as individuals. I enjoy earning their trust and getting to know them as well as helping to navigate their child’s successes and challenges. I take pride in making sure we have full and open communication in our visits and your visit never feels rushed. My mission is to provide our patients with the best and most comprehensive pediatric care possible from birth until 21 years of age. I adhere to the “Golden Rule” in my life and practice which is the principle of treating others as one wants to be treated. Outside of work I enjoy exercising, horse back riding, and spending time with my family. I am an avid animal lover and we have many animals in our family.

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.