“Primary care is about patient advocacy, education, empowerment, and compassionate care. Those are empty buzzwords without listening to patients, understanding them and acting in their best interest.”

Board Certification

  • Internal Medicine

Area of Expertise

  • Primary Care



Georgetown University Hospital
Internal Medicine
Washington, DC


Dartmouth-Mary Hitchcock Medical Center
Internal Medicine
Lebanon, NH

Medical School

Georgetown University
Doctor of Medicine
Washington, DC

Undergraduate School

Bucknell University
Bachelor of the Arts, English
Lewisburg, PA

Hospitals Affiliated With

Georgetown University Hospital
Sibley Memorial Hospital

Honor Society

Alpha Omega Alpha

Academic Appointment

Georgetown University
Clinical Instructor, Department of Medicine
1990 – 2016

Personal Interests

To Dr. Cullen, his family is above all other interests. He owns golf clubs and 1/8 of a boat.


Dr. Dennis Cullen was born and raised in Washington, DC. He was educated at Blessed Sacrament and Georgetown Prep, only important to other natives. He obtained a B.A. at Bucknell University, M.D. at Georgetown University, and post-doctoral training at Dartmouth University and Georgetown.

He served as Chief Medical Officer of the DEA and four years in the National Health Service prior to returning to practice with Drs. Cullen and Umosella. He is in his tenth year as Assistant Team Physician and Team Internist for the Washington Nationals.