She played for the Harvard Crimson women's ice hockey program from 1999-2003. In those four years, she missed only one game. She was the team captain in her junior year. In her senior year, the Harvard defense allowed 1.47 goals per game, the lowest in the NCAA. In 2004, she would become an assistant coach for the Crimson.
Her first experience with USA Hockey was winning a Gold Medal at the 2003 Four Nations Cup. Jamie Hagerman won a gold medal with Team USA at the 2005 IIHF Women's Ice Hockey championships. She registered one assist and a plus-minus rating of plus-5. In addition, she participated at the 2005 Four Nations Cup in Finland and won a silver medal. She led all USA players with a plus-minus rating of plus-8. Hagerman has participated in six USA Hockey National Women's Festivals (the first in 1998, the others from 2000–05).