Ten acts are left and $1 million is on the line. The catch: the winner isn't named until the night after they perform.
The live finale runs Tuesday, Sept. 22 at 9/8c on NBC — an hour later than AGT's usual slot, because The Voice takes the 8 p.m. hour.
Six semifinal winners join four Golden Buzzer acts: singers, magicians, two dog acts, an aerial pole artist, a laser crew and a squad of robots.
Hundred Fingers (magic), Lai Noelle (singer), Nene Royal (rock musician) and Unitree (martial-arts robots) rode Golden Buzzers straight to the final.
Acro Canine Crew, Come Here, Geno Ploeger, Olivia Befus, Royal Lasers and Veronika Goroshkova claimed the six remaining finale spots.
Results night is Wednesday, Sept. 23 at 9/8c. Host Terry Crews reveals the Season 21 champion once America's votes are counted.
NBC carries both nights, and both stream live on Peacock. Live-TV services that include your local NBC station work too.
Voting opens during Tuesday's broadcast. Fans vote at no cost on NBC.com and in the America's Got Talent app, and results are held for Wednesday.
The champion takes the show's $1 million grand prize. Since Season 3, winners have also had a shot at headlining a show on the Las Vegas Strip.
Howie Mandel is on his 17th season, Simon Cowell his 11th, Mel B her 8th and Sofia Vergara her 7th. Crews has hosted for eight straight years.
Season 21 opened June 2 with a summer of auditions. It closes Wednesday with one act, one check and the title.