The Cleveland Cavaliers are believed to be the front-runner to sign Wade.
Wade, 35, was slated to make $23.8 million with the Bulls in 2017-18. Once he clears waivers, he can listen to offers and decide which team is a good fit for him.
According to ESPN's Adrian Wojnarowski, Wade gave up approximately $8 million in salary in order to obtain the buyout.
The Cleveland Plain Dealer reported that the Heat and Spurs could pay $1 million to $2 million more than the Cavaliers, whose offer would be limited to $2.55 million per their salary-cap situation.
Wade played for the Heat during the first 13 seasons of his career, winning three NBA championships. He spent last season with his hometown Bulls after leaving Miami as a free agent in 2016.
The eight-time All-Star averaged 18.2 points and shot 43.4 percent from the field with the Bulls last season.
Wade recently worked out with LeBron James, his former teammate in Miami who left for Cleveland in 2014.
James posted on Instagram after working out with Wade recently: "To say we had a great week of work would be an understatement. We both helped push each other to go outside of our comfort zones. #Itjusfeelsdifferent #Year15 #Brotherhood."
With NBA preseason camps opening soon, Wade is expected to work out a deal quickly. He likely would have to accept a limited role with an NBA title contender.