In this May 4, 2009 AP file photo, Billy Joel and Katie Lee Joel.
In a statement, the pair said that they remain "caring friends with admiration and respect for each other." They got married five years ago at Joel's mansion on New York's Long Island.
A representative for Joel did not immediately respond to the question of whether the couple were getting a divorce.
This was the singer's third marriage, her first.
The 60-year-old Joel is one of pop's most successful singer-songwriters; Katie Lee Joel hosted the first season of reality TV show Top Chef. He recorded the song All My Life as an anniversary gift to his 27-year-old wife two years ago.
