Texas

Barnes was hired by Texas in April 1998, and the basketball program immediately displayed his impact.^[8] Despite playing with just seven scholarship players for the majority of the 1998–99 season and opening the season with a 3–8 record, the Longhorns won 16 of their final 21 games, winning the regular season Big 12 conference championship by a two-game margin, and finishing the year at 19–13 and qualifying for the NCAA Tournament.^[9]

Barnes' success at Texas, a traditional football powerhouse, sparked interest in college basketball at the university and throughout the state. At Texas, Barnes won a school-record 402 games^[10] and transformed the school into one of the top college basketball programs in the nation. He guided the Longhorns to 16 NCAA tournament appearances.^[11] They reached the Final Four in 2003, their first in over 50 years, and advanced to the Elite Eight in 2006 and 2008.^[10][12] He also led Texas to their first #1 ranking in 2010, and led the Longhorns to the first 30-win seasons in school history. He coached two national players of the year: T. J. Ford (2003) and Kevin Durant (2007).^[10] He also won four Big 12 Coach of the Year awards (1999, 2003, 2008, 2014) during his time in Austin, establishing himself as a nationally regarded coach.^[13] He was fired in 2015 after Texas failed to advance to the Sweet 16 for the seventh straight season.^[14][15]

Tennessee

Barnes was hired by the Tennessee Volunteers in 2015.^[16] He was the Vols' third coach in as many seasons. Cuonzo Martin had left for California after the 2013–14 season; his successor, Donnie Tyndall, had been fired after just one season for lying about NCAA violations at his previous stop, Southern Mississippi.^[17][18]

Barnes increased the Vols' win total in each of his first four seasons.^[14] In 2018, he was named Southeastern Conference Coach of the Year after leading the Volunteers to a share of their first regular-season SEC title in a decade and a spot in the conference championship game, earning his sixth-career conference coach of the year award.^[19][20][21]

In 2018–19, he was named the Naismith College Coach of the Year after the Vols finished 31–6 (tying a school record for wins in a season) and reached the Sweet 16 of the NCAA Tournament.^[22][23][24] They were ranked No. 1 for several weeks during the season, only the second time that the Vols have been ranked that high.^[14][25] He coached Grant Williams in his All-American season.^[26] Williams was Tennessee's first player to be named a first-team All American since Dale Ellis in the 1982–83 season.^[27]

In the 2019–20 season, Barnes won his 700th game as a head coach with a victory over Jacksonville State.^[28] In the 2021–22 season, Barnes led Tennessee to their first SEC Tournament title since the 1978–79 season.^[29][30]

In the 2023–24 season, Barnes earned his 800th career win as a head coach in a victory over Texas A&M.^[31] The Volunteers won the SEC regular season outright for the sixth time in school history.