The NBA will launch a coach's challenge system during Summer League and anticipate the rule being used during the 19-20 season.

Coaches will get one challenge per game that they will lose even if the challenge is successful. The challenge can be used to for fouls, goaltending, basket interference, and plays when the ball is knocked out of bounds. The NBA has tested this version of the challenge in the G League.

The coach must "twirl his/her index finger toward the referees" to signal for the challenge. The team must have an available timeout to initiate the challenge