Dr. Mary O’Brien has been a practicing primary care physician in New York City for the past 35 years – first as associate director of an urban emergency department for 10 years and now as a primary care physician at Columbia. She is double-boarded in internal medicine and emergency medicine. For several summers she has volunteered at a rural clinic in the Mississippi while the medical director takes vacation time. She currently precepts fourth-year medical students at Columbia in their primary care rotation. A member of the board of directors of Physicians for a National Health Program, Dr. O’Brien is also a member of the New York Metro chapter’s executive committee.