Most NCAA March Madness brackets close right when the first Round of 64 game tips off, so the practical deadline is just before the opening game of the main tournament each year.

Quick Scoop

  • Brackets usually lock at the scheduled start time of the first Round of 64 game, not during the First Four.
  • For 2026, one major outlet lists deadlines of:
    • Men’s bracket: March 19, 12 p.m. ET.
* Women’s bracket: March 20, 11 a.m. ET.
  • After that first game in each tournament starts, you typically can’t create or edit brackets for those contests.

Why the time can vary

  • Different platforms (ESPN, CBS, Yahoo, office pools, sportsbooks) can set their own lock times, usually matching or slightly preceding tipoff of the first game they cover.
  • Some private/office pools might close earlier (for example, the night before) to avoid last‑minute changes or technical issues.

What you should do this year

  1. Check the official rules or FAQ of the site/app or pool you’re using (look for “bracket lock time” or “submission deadline”).
  1. Aim to have your picks done at least a few hours before the first Round of 64 game to avoid server slowdowns and last‑second rush.

In simple terms: brackets close when March Madness really starts — as soon as that first main‑tournament game tips off. Information gathered from public forums or data available on the internet and portrayed here.