“My approach to patient care is grounded in the belief that the doctor-patient relationship is the foundation of all successful healthcare. Listening to the patient has always been the most important diagnostic test.”

Board Certifications

  • Internal Medicine
  • Pediatrics



Geisinger Medical Center
Internal Medicine/Pediatrics
Danville, PA

Medical School

Georgetown University School of Medicine
Doctor of Medicine
Washington, DC

Undergraduate School

La Salle University
Bachelor of the Arts, Biology/English
Philadelphia, PA

Hospital Affiliated With

Sibley Memorial Hospital

Personal Interests

Dr. Cullen and his wife, Brenda, have six children.


Dr. Cullen is a native Washingtonian. His parents moved down from Scranton, PA when his father attended Georgetown Medical School. He grew up in Northwest DC and went to Blessed Sacrament Grade School. Dr. Cullen went on to attend Gonzaga College High School, La Salle University, and Georgetown Medical School. He completed a four-year combined residency in internal medicine/pediatrics at Geisinger Medical Center. Then served as chief resident in his final year. He achieved board certification in both specialties. Dr. Cullen moved home to DC in 1997 to join the practice that his father had started to work with his siblings, Edward and Dennis, and Charles Umosella. They provide primary care medicine in the same community they grew up in.