How does the Instant Replay System work, and what can the head coach challenge?

Question

Accepted Answer

Where the Instant Replay System (IRS) is used (Appendix F):

The crew chief decides whether a review is used, and starts it as fast as possible after gathering information from the other referees and table officials. The crew chief and at least the umpire who made the call take part.
The referees must show their initial decision on court. It can be corrected only if the review gives clear and conclusive visual evidence.
The review happens before time-outs or substitutions are administered or the game resumes.
Any time: whether a goal was a 2 or 3-point shot, the number of free throws after a foul on a shooter, whether a personal, disruptive, flagrant or disqualifying foul met its criteria, correctable errors, clock malfunctions, the free-throw shooter, and involvement in violence.
Last 2:00 of the fourth quarter and each overtime: whether a goal was released before the shot clock sounded, and whether the thrower-in still held the ball when a defensive foul occurred on a throw-in.
New in 2026: goaltending or basket interference after a foul can be reviewed at any point in the game.
Head coach's challenge: where the IRS is used, the head coach may ask the nearest referee to verify a decision with the IRS. The head coach is granted only one challenge in a game.