Patrick Reed, Zach Johnson and Brandt Snedeker earned the final three automatic Ryder Cup spots for the United States.
The nine automatic European spots had already been filled, but only five players on the USA team were guaranteed a place before the points closed on Sunday following The Barclays.
Reed earned a spot by winning his first event of the season.
Reed, Johnson and Snedeker joined Brooks Koepka, Jordan Spieth, Dustin Johnson, Jimmy Walker and Phil Mickelson in the team.
Captain Davis Love III will make three of his four picks after the conclusion of the BMW Championship.
He will then make his fourth and final pick at the end of the Tour Championship.
Big names such as Bubba Watson, Matt Kuchar and Rickie Fowler, who failed to finish in the top three and earn an automatic spot this week despite entering the final round with a one-shot lead, will be anxiously awaiting Love's decision.
J.B. Holmes, Justin Thomas, vice-captain Jim Furyk and Billy Horschel are also in contention for selection.