Tagge played professionally with the Green Bay Packers of the NFL from 1972 to 1974, the San Antonio Wings of the WFL in 1975, and the BC Lions of the CFL from 1977 to 1979.
His playing time increased until midway through his junior year when he took over the starting position from Van Brownson, leading the team to a 10–0–1 season and a matchup with LSU in the 1971 Orange Bowl.
Tagge scored the game-winning touchdown in a 17–12 victory over the Tigers on a quarterback sneak, earning himself Most Valuable Player honors, and the Huskers the AP national championship for 1970.
Nebraska crushed undefeated Alabama, 38–6, in the 1972 Orange Bowl, earning Tagge MVP honors for the second time.
Tagge was the first of three Nebraska Cornhuskers selected in the first round of the 1972 NFL draft, along with running back Jeff Kinney and defensive tackle Larry Jacobson.
Tagge's performance earned the notice of Dan Devine, head coach of the Green Bay Packers.
Tagge did not enjoy the success in his hometown that he had at Nebraska, completing only three touchdown passes in 17 games played during three seasons from 1972 to 1974.
He returned to Nebraska in 1986, initially selling life insurance, then founded Tagge-Rutherford Financial Services in Omaha, for which he serves as executive vice president.