By Helen Ross, PGATOUR.COM

Ryo Ishikawa has taken up special temporary membership on the PGA TOUR for the remainder of the 2011 season. That means he may accept unlimited sponsor's exemptions for the rest of the year.

The 19-year-old from Japan has played in 10 PGA TOUR events this year and has earned $577,136 – the bulk of that coming two weeks ago at the World Golf Championships-Bridgestone Invitational where he tied for fourth. Ishikawa earned $473,136 at Firestone.

Since his earnings are  greater than the player who finished No. 150 on the money list a year ago, Ishikawa became eligible for Special Temporary Membership.

To join as a fully-exempt member next year without going to qualifying school, Ishikawa needs to earn enough money to be equal or be greater than the player who finished at No. 125 on this year's PGA TOUR money list.

Billy Mayfair currently owns that spot with $538,493. But there is one event remaining in the TOUR's regular season, four events in the PGA TOUR Playoffs for the FedExCup and four events in the Fall Series.

Ishikawa is not eligible for the Playoffs but he can play in the Fall Series. The player who finished at No. 125 a year ago earned $786,977.