John Catlin, an American who's won three times in his past 14 starts on the European Tour, also received a special invite to join the field headed to Kiawah Island.
"Rickie Fowler and John Catlin were granted special invitations to the 2021 PGA Championship based on their performances, playing records, and OWGR position," a spokesperson told Beall.
Fowler is ranked No. 111 in the Official World Golf Ranking and would need to jump inside the top 100 by May 10. His position on the 2018 U.S. Ryder Cup team would have secured his spot in the major, but the exemption was dependant on him remaining inside the top 100 in the world.
He's not in this week's Valspar Championship field and would need to rely on his result in next week's Wells Fargo Championship at Quail Hollow to make the jump back inside the top 100.
Additionally, Fowler ranks 128th on the PGA Championship points list and would need to vault inside the top 70 by the same May 10 deadline.
Fowler didn't play in the 2021 Masters, which marked his first missed major championship since the 2010 U.S. Open. He hasn't won on the PGA TOUR since the 2019 Phoenix Open and doesn't have a top-10 finish worldwide since January 2020.
The 2021 PGA Championship from Kiawah Island in South Carolina begins on May 20.