Early and collegiate The son of Tom and Barbara, Jahn attended
Jesuit High School in
Carmichael, California, where he played soccer. He was named the Gatorade California Player of the Year in 2007 and 2008, in addition to being named a
NSCAA All-American. He continued his education and soccer career at
Stanford University, where he played all four years, scoring 24 goals and 12 assists. In his senior year, he was named to the All-
Pac-12 first team. Jahn played his youth club soccer at the Davis Legacy Soccer Club from 2000 through 2008.
San Jose Earthquakes Jahn was selected as the 15th pick in the
2013 MLS Supplemental Draft by his local team, the
San Jose Earthquakes, on January 22, 2013. On March 3, 2013, Jahn made his debut for the Earthquakes at
Buck Shaw Stadium in the opening game of the season by coming on as a substitute in the 83rd minute for
Ty Harden. San Jose lost the match 2–0 against
Real Salt Lake. He scored his first professional goal in his next game against the
New York Red Bulls. The goal came in the form of a right-footed
volley off a far-post
cross from
Sam Cronin in the 83rd minute to tie the game. On a subsequent play, he headed the ball into the hand of
Roy Miller, setting up the winning
penalty kick by
Chris Wondolowski to complete a 2–1 comeback victory.
Columbus Crew SC On July 30, 2016, Jahn was traded to
Columbus Crew SC in exchange for Targeted Allocation Money. He made his club debut the next day, coming on as a substitute in a 3–0 loss to
Toronto FC. Jahn scored his first Crew SC goal in a 2–1 loss to the
Philadelphia Union, after coming on as a substitute with 30 minutes to play. At the end of the 2018 season, the club declined Jahn's contract option; he departed Columbus with seven goals from 46 total appearances.
Phoenix Rising FC Jahn signed with
Phoenix Rising FC on December 10, 2018. Jahn scored 17 goals, which was 5th in the league, and added 5 assists.
Atlanta United FC On January 22, 2020, Jahn was acquired by
Atlanta United. The transfer fee was undisclosed, but it was reportedly $100,000. Jahn was waived by Atlanta on February 2, 2021.
Orange County SC On February 22, 2021, Jahn joined USL Championship side
Orange County SC, technically on loan from Atlanta United, although he had recently been waived by the MLS club. ==Career statistics==