The PGA Championship has been a stroke-play tournament since its change of format in 1958. A maximum of 156 golfers participate in the tournament, which consists of four rounds of 18 holes. After the first 36 holes of play, the field is reduced to the best 70 scorers (and ties). Those players compete in the final two rounds, with the lowest score winning the championship.

If there is a tie for first place after all 72 holes have been completed, the tournament will be decided by a three-hole, aggregate-score playoff on holes Nos. 10, 17 and 18. If a tie remains, a hole-by-hole playoff will begin on hole No. 10 and move to Nos. 17 and 18 until a winner is decided.

The tournament follows the rules of golf as set by the United States Golf Association and applied by the PGA of America Board of Directors, which ultimately oversees the entire PGA Championship.

Qualifications The PGA of America selects a list of players eligible to compete in the PGA Championship, consisting of former champions, winners of other major events and club professionals who qualify through a national championship. The full list in 2010 includes:

- All former PGA Champions

- Winners of the past five Masters (2006-10)

- Winners of the past five U.S. Opens (2006-10)

- Winners of the past five Open Championships (2006-10)

- The last Senior PGA Champion

- The lowest 15 scorers and ties in the 2009 PGA Championship

- The 20 lowest scorers in the 2010 PGA Professional National Championship

- The top 70 money winners on the PGA Tour in the period one week prior to the 2009 PGA Championship through two weeks prior to the 2010 PGA Championship

- Members of the most recent Ryder Cup teams, as long as they are in the top 100 of the Official World Golf Rankings

- Winners of tournaments co-sponsored or approved by the PGA Tour from the 2009 PGA Championship to the 2010 PGA Championship (excluding pro-am and team competitions)

- Vacancies will be filled by the first available player from the list of alternates (those below 70th place in the Championship Points list from the 2009 World Golf Championships-Bridgestone International through the 2010 Greenbrier Classic)

The PGA can invite other players, not included in those categories, to fill out the total field, which cannot exceed 156 players. Usually every golfer ranked in the world top 100 can count on a spot at the Championship. The PGA Championship is the only major that does not invite leading amateurs to compete (although they still can qualify by winning another major), having been created as a showcase event for professional golfers rather than wealthy amateurs.

In order to continue its commitment to club golfers, the PGA Championship reserves 20 spots (more than any other tournament) for golfers from the PGA club championship, which allows PGA of America members to qualify apart from the touring members.