“ER” RAN FOR 15 SEASONS AND NOT A SINGLE ORIGINAL CAST MEMBER WAS ON ALL OF THEM
Actor Noah Wyle was a main cast member for 11 seasons, the longest tenure of any original cast member. Anthony Edwards and Eriq La Salle were both on for the first eight seasons. Popular “ER” actor George Clooney was only a main cast member for the first five seasons. Julianna Margulies left during season six.