The game clock in the NFL stops in several specific situations, mainly to manage fairness and game flow near key moments.

Core answer

The clock stops in the NFL when certain events happen: incomplete passes, players going out of bounds in specific time windows, timeouts, penalties, injuries, changes of possession, scores, and on some replay reviews.

Main situations the clock stops

  • Incomplete pass – Any forward pass that hits the ground stops the clock until the next snap.
  • Player out of bounds –
    • Clock stops briefly when a runner goes out of bounds, then usually restarts when the ball is set and the referee signals ready-for-play.
* After the two-minute warning of the first half and inside the last five minutes of the second half, the clock stops and stays stopped until the next snap, making late-game clock management more critical.
  • Timeouts –
    • Each team gets three timeouts per half; calling one stops the clock for about 60 seconds.
* There are also automatic time stoppages like the two-minute warning in each half.

Other clock-stoppage events

  • Change of possession – Turnovers, punts, and kickoffs that result in the other team gaining the ball stop the clock.
  • Scores – Touchdowns, field goals, safeties, and extra points or two-point tries lead to dead-ball periods with the clock stopped until the next kickoff or snap.
  • Injuries and penalties –
    • Officials stop the clock for injuries, measurements, and penalty enforcement.
* In the final two minutes of the first half and final five of the second, some offensive penalties can trigger a 10‑second runoff unless a timeout is used.
  • Replay reviews and challenges – The clock stops during official reviews and coach’s challenges and restarts on the referee’s signal, usually on the next snap.

Special out-of-bounds nuance

  • After the two-minute warning of the first half and in the last five minutes of the fourth quarter, the clock normally stays stopped when a runner goes out of bounds until the snap.
  • Key exception: if the runner is driven or goes backward out of bounds after contact, the clock can continue to run even in those late-game windows, to prevent cheap stoppages.

Information gathered from public forums or data available on the internet and portrayed here.