Susan Sarandon, George Clooney, Julianna Margulies Set for March 12 ER

Sarandon, the only one of the quintet not to have been a series regular, is currently starring on Broadway in Exit the King. Margulies, who played nurse Carol Hathaway for six years, starred on Broadway in Festen.

The Emmy-Award winning series, about life in a hospital emergency room, is currently finishing up its final season, having debuted on NBC in 1994. Other veteran cast members are expected to appear in its remaining episodes.