Jeff Halpern spent four successful years with Princeton University where he developed a knack for putting the puck in the net. His ability to score caught the attention of the Washington Capitals and when his collegiate career ended they signed him to as a free agent. He joined their farm team, the Portland Pirates to finish out the 1998-99 campaign and was able to score two goals and add an assist in six games.
The following year he joined the Capitals full-time and enjoyed immediate success in the NHL when paired with veterans Steve Konalwalchuk and Ulf Dahlen. Halpern scored 18 goals and 29 points in 79 games and then added two more goals and an assist in five playoff games.
The next season he elevated his play a little further by eclipsing the twenty goal plateau with 21 markers and the same amount of assists. In the playoffs he again showed that he was a clutch performer with two goals and five points in six games.
Things went wrong for Washington, and for Halpern, once the 2001-02 schedule began. Halpern struggled out of the gate to find his game, and things got worse when he was removed from the Konalwalchuk-Dahlen line. A bad season went worse when Halpern tore ligaments in his knee during a game in Montreal and was lost for the rest of the campaign. In the end he played 48 games and managed just five goals and 19 points before returning to form in 2002-03.
In 2003-04 the Caps struggles continued with the team opting to trade their core players. Names such as Lang, Gonchar, Bondra, Jagr and Konowalchuk were traded away, while Halpern remained as one of the bright spots in a dismal season for the the Caps. After failing to qualify for the post season, Halpern joined the U.S. World Championship team in Prague, Czech Republic and was a key player in the team's bronze medal performance.
Halpern's stint with Washington came to an end in the summer of 2006 when the centreman signed as a free agent with the Dallas Stars. As a member of the Stars, Halpern suited up in 140 games, including his 500th NHL game, before he was dealt at the NHL trading deadline. On February 26, 2008 Halpern was sent to the Tampa Bay Lightning along with Mike Smith and Jussi Jokinen, for Brad Richards and Johan Holmqvist.
Aside from his World Championship appearances in 2004 and 2008, Halpern has gone on to represent his homeland on several occasions at the Worlds (2000, 2001 and 2005) and was a member of the U.S. World Cup team in 2004.
On March 3, 2010, the NHL trade deadline, the veteran Halpern was traded to the Los Angeles Kings in effort to bring some added experience to the youthful Kings lineup. He would not spend much time on the west coast however, he signed a one-year deal with the Montreal Canadiens on September 7, 2010.
In the summer of 2011, Halpern would return to where he had his most productive NHL seasons. On July, 1, 2011, he inked a one-year deal with the Washington Capitals.