The suspended guard submitted paperwork to go from No. 0 to No. 6, and the NBA approved the change, league spokesman Tim Frank confirmed in an email to The Associated Press on Thursday.
Arenas has worn zero since college, saying he picked that number because that’s how many minutes people expected him to play at Arizona.
Last Friday was the deadline for NBA players to file paperwork seeking a new number. Cavaliers star LeBron James asked to switch from No. 23 to No. 6 next season.
Arenas was given a season-ending suspension by the NBA for bringing guns to the locker room. He pleaded guilty to a felony gun possession charge in January and is scheduled to be sentenced March 26.