Up to 24 U.S. bishops, including two cardinals, could retire because of age this year, reported the Georgia Bulletin.

There are 11 active U.S. bishops, including one cardinal, who have already turned 75. Thirteen more will celebrate their 75th birthday in 2010. At the age of 75, bishops are requested to submit their resignation to the pope.

Among the potential retirees are: Cardinal Bernard Law, archpriest of St. Mary Major Basilica in Rome, and former Archbishop of Boston, who turned 75 on Nov. 4, 2006; and Cardinal Justin Rigali of Philadelphia who turns 75 on April 19.

Cardinals have often been asked to stay on the job after the age of 75. Even if retired, a cardinal remains an active member of the College of Cardinals until the age of 80.