The PGA Championship playoff format is distinctly different from the Masters, U.S. Open or British Open.
At the PGA Championship, if two or more golfers are tied after 72 holes, they’ll enter a three-hole aggregate playoff, where the lowest total score over the three holes wins. If two or more players are still tied after the three holes, they’ll enter a sudden-death playoff for the Wanamaker.
The Masters uses a sudden-death playoff, the U.S. Open calls for a two-hole aggregate (2018 was the first year for this) and the British Open uses a four-hole aggregate. The PGA was last decided by a playoff in 2011, when Keegan Bradley beat Jason Dufner at the Atlanta Athletic Club.