Nate McMillan was fired as coach of the Atlanta Hawks after guiding the NBA club to a 29-30 start to the 2022-23 campaign, the team announced Tuesday.
Hawks general manager Landry Fields said assistant coach Joe Prunty would serve as the interim head coach.
"Decisions like these, especially in-season, are always extremely difficult, but we believe it's in the best interest of our team to move forward with another voice leading the way," Fields said.
McMillan finished with a 99-80 record as coach of the Hawks, having started as an interim coach after a mid-season firing in 2021 and guiding Atlanta to the Eastern Conference finals.
"I would like to thank Nate for his leadership and professionalism during his time with the Hawks," Fields said.
"He's truly a class act and we appreciate the graciousness and work ethic he brought."
McMillan, who played 12 NBA seasons as a guard for the Seattle SuperSonics, was in his 19th season as an NBA head coach after stops in Seattle, Portland, Indiana, and Atlanta from 2001.
McMillan, an assistant coach on the US 2008 and 2012 Olympic gold medal teams of NBA stars, has compiled a career NBA coaching record of 760-668.
McMillan was an assistant coach for the Hawks when Lloyd Pierce was fired and McMillan was named an interim head coach in March 2021.
The Hawks finished the campaign 27-11 under McMillan and advanced past the second round of the NBA playoffs for only the second time in 54 years, ousting New York and Philadelphia before falling to eventual champion Milwaukee in the Eastern Conference finals.
It was his deepest career playoff run as a coach.
MacMillan was rewarded by being named the new head coach in July but the Hawks lost to Miami in last year's first round of the playoffs and had only struggled to eighth in the Eastern Conference standings at the All-Star Game break.
Prunty, 54, joined the Hawks as an assistant coach in July 2021. He had been an assistant NBA coach since 1996 except for two stints as an interim head coach for Milwaukee in which he went 29-25.
He was an assistant coach on three NBA championship clubs in San Antonio from 1999-2005.