The NCAA Men's Division I Basketball Championship is held each spring featuring 64 college basketball teams in the United States.

The 20-day tournament, colloquially known as March Madness or the Big Dance, has become one of the United States' most prominent sports events.

The tournament, whose field includes regional conference champions and other top teams, is staged in a single elimination format. Since its 1939 inception, it has built a legacy that includes dynasty teams and dramatic underdog stories. In recent years, friendly wagering on the event has become something of a national pastime, spawning countless "office pools" that attract expert fans and novices alike. All games of the tournament are broadcast on the CBS broadcast television network in the United States, except for the Opening Round game (or "play-in game" as it has been called), which aired on TNN in 2001, and ESPN since 2002.

The tournament bracket is made up of champions from each Division I conference, which receive automatic bids. The remaining slots are at-large berths, with teams chosen by an NCAA selection committee. The selection process and tournament seedings are based on several factors, including team rankings, win-loss records and RPI data.

The two lowest-seeded teams (typically teams with poor records that qualified by winning their conference tournament championships) play a pre-tournament game to determine which will advance into the first round of the tournament, with the winner advancing to play the top seed in one of the four regions. This play-in game was added in 2001 and has been played in University of Dayton Arena in Dayton, Ohio each subsequent year.

A Most Outstanding Player honor is awarded by the Associated Press at the end of each tournament.