Who We Are

When you come to our office, we’ll learn a lot about you, so here’s a little bit about us.

Michael A. McCormick, D.O.

Dr. McCormick is the president and owner of Express Med of King of Prussia. Michael grew up in Audubon, PA and now resides in Wayne, PA with his wife, Nicole, and their five children. Dr. McCormick graduated from St. Joseph’s University, before attending and graduating from the Philadelphia College of Osteopathic Medicine in 1999. He trained at Lankenau Hospital in their rigorous general surgery residency program and afterwards accepted a position as an attending surgeon at Helen Keller Hospital in Muscle Shoals, Alabama.

He built a very large and successful solo practice over the seven years of living in the South and was one of the youngest people to ever serve as chief of surgery and on the Medical Executive Committee of the hospital.

In August 2012, the McCormick family decided it was time to “return home” to the Philadelphia area. This was also when Dr. McCormick decided it was time for a career change. The McCormick’s decided that given the ever changing delivery of healthcare, it was time to open an urgent care center. After extensive research and careful consideration the McCormick’s decided to bring their first Express Med to Michael’s childhood backyard of King of Prussia.

Dr. McCormick’s primary goal for Express Med of King of Prussia is to combine exceptional customer service with compassionate medical care. We are happy to see you at all times, especially when you are not at your best!


Margaret E. Marcinik, D.O.

Dr. Marcinik has had a long and successful career as a board certified Emergency Room physician.

She attended the University of Medicine and Dentistry of New Jersey / New Jersey School of Osteopathic Medicine, where she graduated in 1990. She then completed her residency at the rigorous Geisenger Medical Center.

Dr. “Peg” has been on staff at Crozer Chester Medical Center since 2005. She was the Director of Express Care Unit there from 2006 until 2010. She currently is the Chair PICIS subcommittee of the eCare Governance Committee.

Dr. Marcinik currently resides in the Media, Pennsylvania area.


Christopher Marsh, P.A.

Christopher Marsh is a certified physician assistant, practicing since 2010. He is originally from southern New Jersey, but currently lives in the King of Prussia area. He holds a Bachelor of Science in Biology from Philadelphia University, a Master’s certificate in clinical research from Drexel University, and a Master’s degree in physician assistant studies from Salus University.

Marsh has worked in family practice, urgent care, and emergency medicine, and he is on staff at two local hospitals.

He enjoys spending his free time with family and friends, and he frequents the beaches at the Jersey Shore.  Marsh likes to devote time to staying physically active, spending his off days running and working out at the gym. He has also played semi-professional football.