His first game as a Hurricane was against Madison High School, and Augustin nearly pulled off a triple-double with 29 points, 8 rebounds and 14 assists in an 83–59 victory.

Augustin finished his high school career by being named a McDonald's All American, and started as point guard for the West squad against his soon to be teammate at Texas, Kevin Durant.

Augustin, along with Texas A&M Aggies player Joseph Jones, was featured on the front cover of the November 15, 2007 issue of Sports Illustrated.

[12] On October 30, he made his professional debut in a 96–79 loss to the Cleveland Cavaliers, recording 12 points and two assists in 25 minutes.

[16] The 2010–11 season would be arguably the most productive of Augustin's career, as he started all 82 games while averaging 33.6 minutes, scoring 14.4 points and recording 6.1 assists per contest.

[21] On October 31, he made his debut with the Pacers in a 90–88 win over the Toronto Raptors, recording five points, one rebound, two assists and one steal in 15 minutes.

[29][30] On January 25, 2015, in his first game as a starter, replacing the injured Brandon Jennings, Augustin scored a career-high 35 points in a 110–114 loss to the Toronto Raptors.

[31]On February 19, 2015, Augustin was traded to the Oklahoma City Thunder in a three-team deal that also involved the Utah Jazz, a move that reunited him with his ex-college teammate Kevin Durant.

[32] Two days later, he made his debut for the Thunder in a 110–103 win over the Charlotte Hornets, recording 12 points, three rebounds and two assists in 23 minutes off the bench.

[33] On February 18, 2016, Augustin was traded, along with Steve Novak, two second-round picks and cash consideration, to the Denver Nuggets in exchange for Randy Foye.

[34] The next day, he made his debut for the Nuggets in a 116–110 loss to the Sacramento Kings, recording eight points, six assists and three steals in 19 minutes.

[44] On April 13, 2019, Augustin scored 25 points and hit the game-winning 3-pointer in the Magic's 104–101 upset victory over the Toronto Raptors in game one of the first round of the playoffs.

[46] The following season in the NBA Bubble, in another round one upset victory, Augustin helped the Magic beat the top-seeded Milwaukee Bucks with 11 points and 11 assists in a 122-110 Game 1 win.

[49] He made his debut for the team on December 25, scoring 13 points in a 138–99 Christmas Day win over the Golden State Warriors.

[50] On March 18, 2021, Augustin was traded, alongside D. J. Wilson and a 2023 first-round pick, to the Houston Rockets in exchange for P. J. Tucker and Rodions Kurucs.

[56] He made his debut for the team two days later, logging three points, six assists and three steals in a 111–132 loss to the Los Angeles Clippers.