What can an NBA coach challenge, and how many challenges are there?

How many (Rule 14 Section I): each team has one challenge per game. If the first challenge is successful, the team is awarded a second.

What can be challenged: only three events:

1. A called personal foul charged to the challenging team.
2. A called out-of-bounds violation where the challenging team was not awarded possession.
3. A called goaltending or basket interference violation (not in the last two minutes of the fourth period or any overtime, where only on-court officials trigger review).

A challenge is the only way to trigger replay of out-of-bounds violations at any point in the game.

What cannot be challenged: any other call, any non-call, and for example a personal foul charged to the opponents, continuation on its own, a technical or flagrant foul, and violations such as travelling, carrying, double dribble, flopping, and offensive or defensive three seconds.

Source: 2026-27 Official NBA Playing Rules, Rule 14 Section I.