A Colorado official confirmed Hirschman's plans.
Hirschman met with new coach Mike MacIntyre mid-morning Friday and informed him of his decision. He is set to graduate and will pursue graduate work "likely at an Ivy-type school," the official said, noting that Hirschman had received offers from Ivy League schools coming out of Los Gatos High School in the Bay Area.
Hirschman and Wood were the two front-runners this spring, and according to the official, the competition was "too close to call" when the Buffaloes broke camp earlier this week.
Hirschman appeared in seven games last season, completing 55 of 93 passes (59.1 percent) for 589 yards, with two touchdowns and seven interceptions in a 1-11 season.
Colorado shuffled through three quarterbacks last season, with Jordan Webb, a transfer from Kansas, getting the bulk of the snaps, followed by Hirschman and Wood. Webb will miss the 2013 season after tearing his ACL this spring.
Hirschman posted the news Friday on Twitter: "Wednesday I decided to move on from CU and continue my graduate education and football career elsewhere. I loved my time here and the relationships I've had with my fellow teammates I wouldn't trade for anything. Part of me will always be a Buff and thank you to Buffnation for all of the support."