We're a tight-knit group of medical professionals who will get to know you on a first name basis

Justin Holtzman, MD, MHSA


Justin Holtzman, MD is a board-certified internist practicing in the Boston area. He received his Bachelor in Business Administration degree from The University of Michigan Ross School of Business in Ann Arbor, MI. Following his undergrad, he completed combined Master of Health Services Administration and Medical Doctorate degrees at The University of Michigan.  He then went on to complete his internship in Internal Medicine at St. John Hospital and Medical Center in Detroit, MI, followed by a residency in Internal Medicine at the University of Massachusetts Medical School in Worcester, MA.

He has most recently served on the faculty of Harvard Medical School teaching physical exam and clinical reasoning skills to first year medical students. Dr. Holtzman has a passion for primary care, teaching, and delivering the highest quality, evidence-based care to his patients.

Dr. Holtzman also serves as the Director of Hospitalist Medicine for CPS Medical Group, a private physician group that provides in-patient services throughout the region.

On the off chance that he isn't working, he can be found stranded on his boat in Boston Harbor with his friends and family.


Shannon Courage


Medical Assistant

Hailing from Braintree, MA, Shannon has been working in the medical field for over 9 years. In 2010, she graduated from American International College with a certificate in medical assisting. She is currently pursuing a bachelor’s degree in natural science, after which she hopes to continue in the medical arts. Shannon handles the administrative and medical assisting functions at Holtzman Medical Group.

In her spare time, Shannon enjoys spending time with friends, traveling to Florida, and driving her Jeep


Insurance and Billing

Amy Gulner


Amy Gulner grew up in rural Maine, where she developed a strong work ethic and the ability to capture baby swine at the local fair. After high school, she attended The University of Minnesota, receiving a Bachelor of Arts degree in Strategic Communications. Meeting her future husband, and subsequently developing an affinity for warmer weather, Amy escaped to San Diego, CA, where she currently enjoys year-round warmth and sunshine. She lives with her husband, two kids, her dog, Munten, and her cat, Arlo. When not working, she enjoys relaxing, running, and spending time with family.