Hannafin served as a USOC physician for the 2004 Olympic Games in Athens, Greece, a team physician at the 2003 Pan American Games in the Dominican Republic, and an event physician at the 1996 Atlanta Olympic Games. Dr. Hannafin was a team physician for the WUSA New York Power from 2000-2003, an assistant team physician for the New York Mets from 1992-1996, and has been team physician for the U.S. Rowing Team since 1994. Hannafin is a member of the FISA Medical Commission and the Head Team physician for the WNBA New York Liberty. She was also a member of the silver medalist lightweight double at the 1984 World Rowing Championships and a three-time gold medalist at the U.S. National Rowing Championships.