Sean O'Hair is the only American among 12 players not already exempt for the Masters who qualified through the world ranking.
There are no tournaments the rest of the year, so the final 2010 ranking became available Monday.
Among other criteria, the Masters invites players who are in the top 50 at the end of the year. The ranking is mainly for players who are not PGA Tour members and have fewer avenues to qualify, such as winning a tour event or getting into the FedEx Cup finale.
O'Hair started the year No. 15 and did not win a tournament or reach the Tour Championship. He ended the year at No. 43. The other 11 qualifiers include Francesco and Edoardo Molinari, Robert Karlsson, Charl Schwartzel and Ryo Ishikawa.
That brings to 91 the number of players who have qualified for the Masters, which has the smallest field of the four majors. Augusta National prefers to keep its field at about 100.
Players still can qualify for the Masters by getting into the top 50 a week before the tournament, or winning a PGA Tour event that offers full FedEx Cup points.
The Masters will be played April 7-10, with Phil Mickelson the defending champion and Tiger Woods trying to end his longest drought without a major or a green jacket. Woods last won the Masters in 2005, and he has gone 10 majors without winning.