ESPN.com's Adrian Wojnarowski first reported the news.
Budenholzer joined the organization in 2013 after a long career as an assistant with the San Antonio Spurs, quickly transforming the squad into a legitimate contender. After winning 38 games in 2013-14, the Hawks went 60-22 in 2014-15 for the best record in the Eastern Conference.
The squad reached the Eastern Conference Finals that year for the first time since the NBA was divided into conferences in 1970-71, and Budenholzer was named the NBA Coach of the Year.
Unfortunately, the Hawks haven't been able to match that success in recent years, eventually starting a rebuilding process after losing All-Star players to trades and free agency. The coach relinquished his role as president following last season.
Things went further south in the 2017-18 season, with the young roster struggling to the worst record in the East. The organization missed the playoffs for the first time in 11 seasons.
"It's not easy to go through a season that we just had," Budenholzer said after the final game, per Alec McQuade of 11Alive.
The 48-year-old should get plenty of opportunities in the future thanks to his youth and positive experience both as a head coach and assistant, winning four NBA titles in his time in San Antonio. He interviewed with the Phoenix Suns before taking himself out of the mix, per Wojnarowski, while also meeting with the New York Knicks, per Michael Cunningham of the Atlanta Journal-Constitution.
However, Atlanta clearly wanted to go in a different direction as it builds its new team into a contender.
The Hawks have a lot of quality pieces going forward, including Dennis Schroder, John Collins and Taurean Prince, plus a soon-to-be-determined high pick in the 2018 NBA draft. Despite the struggles of this past season, the organization should be able to find several quality candidates willing to fill the role.