Jeff Ament has been a member of Pearl Jam since 1990.
Jeffrey Allen Ament ( born March 10 , 1963 ) is an American musician and songwriter who serves as the bassist for the American rock band Pearl Jam . Pearl Jam is an American rock band formed in Seattle , Washington , in 1990 . Since its inception , the band 's line-up has comprised Eddie Vedder ( lead vocals ) , Mike McCready ( lead guitar ) , Stone Gossard ( rhythm guitar ) and Jeff Ament ( bass ) .