Since retiring from the field, he launched Umbo, a functional mushroom supplement company alongside former UFC Champion Rashad Evans.

[9] As a junior in 1995, his 2,222 yards and 17 touchdowns, many coming at pivotal moments in games, earned him a strong fan base and all-conference honors despite a lackluster 6–5 record.

Arizona State attracted national attention on September 21 when they shut out top-ranked Nebraska 19–0 to snap the Huskers' 26-game winning streak.

[11] He led ASU to an undefeated regular season and a Pac-10 championship,[12] aided in no small part by fellow all-conference linebacker and close personal friend Pat Tillman.

In the Rose Bowl, he scored a sensational 11-yard go-ahead touchdown run late in the fourth quarter, but Ohio State responded and won 20–17.

[4] Plummer was third in the Heisman Trophy voting behind Florida's Danny Wuerffel and Iowa State's Troy Davis,[14] was a first-team All-American, and the Pac-10's Offensive Player of the Year.

He took his first snap late in the 4th quarter of the seventh game, and promptly led the Cardinals on a 98-yard drive, going 4-of-6 for 87 yards and capping it with a 31-yard go-ahead touchdown.

"[4] In 1998, the Cardinals drafted Plummer's friend Pat Tillman, and the two started all sixteen games en route to a 9–7 regular season record.

He was one of only two NFL quarterbacks to take every snap for his team (Kerry Collins was the other), and he passed for 3,653 yards, eighteen touchdowns, and fourteen interceptions.

On September 22, he had the longest run by a Broncos QB on Monday Night Football, a 40-yard scramble in a 31–10 win over the Oakland Raiders.

However, Plummer accounted for four turnovers in the AFC Championship game and the Broncos were defeated 34–17 by the eventual Super Bowl champion Pittsburgh Steelers.

On November 27, 2006, after a lackluster performance in the first eleven games, and following back-to-back losses to the San Diego Chargers and Kansas City Chiefs, head coach Mike Shanahan announced that Plummer would be replaced at starting quarterback by rookie Jay Cutler.

However, rumors began to surface that Plummer was going to choose retirement over competition with the Buccaneers' four other quarterbacks on the roster (Bruce Gradkowski, Tim Rattay, Jeff Garcia, and Luke McCown).

After retiring from the NFL, Plummer moved to Sandpoint, Idaho (though the couple also has a house in Boulder, Colorado) where he lives in relative anonymity.

[4] His former agent Leigh Steinberg said he is "one of the minuscule few that I could see living a completely fulfilled life away from sport... he was as close to an egoless major star as I've seen."

When a concerned Meals on Wheels supervisor in Sandpoint insisted that a jobless, "scruffy", long-time volunteer who worked for her, keep track of the miles he drove for the organization for reimbursement, she was "dumbstruck" to discover he was a former NFL star.

[4] The lifestyle contrasted with the somewhat rocky moments during his playing days with much attention devoted to flipping off a fan, a loud traffic dispute, and a feud with a Denver gossip columnist.

[33] Plummer also started an Alzheimer's foundation, made time during his career to walk dogs at a shelter he donated $10,000 to on retirement, and developed personal connections with children affected by 9/11.

[4] On June 27, 1997, he struck a plea agreement rather than fight charges alleging that he grabbed four women at a nightclub in Tempe, Arizona.

During leave in January 2004, the two showed up unannounced at a handball tournament in Seattle in support of Jake's brother, Eric.

Plummer by this point was with the Broncos, requested to wear the decal for the entire season, but the NFL turned him down because his helmet would not be the same as the rest of his team.

[4] Plummer uses cannabidiol (CBD) to treat the pain, inflammation, and headaches that he has experienced as a result of his years playing football.

[40] In November 2016, Plummer was one of the signatories of an open letter addressed to the NFL, urging a change in the league's policy towards cannabis.