ER Reunion: George Clooney, Julianna Margulies & More | 4/22/21 8pm ET | Stars in The House | PEOPLE

The reunion episode will feature cast members Gloria Reuben (Jeanie Boulet), George Clooney (Doug Ross), Noah Wyle (John Carter), Laura Innes (Kerry Weaver), Anthony Edwards (Mark Greene), Alex Kingston (Elizabeth Corday), Julianna Margulies (Carol Hathaway), Goran Visnjic (Luka Kovac), Paul McCrane (Robert Romano), Ming-Na Wen (Jing-Mei Chen), Laura Cerón (Chuny Marquez), Yvette Freeman (Haleh Adams), Conni Marie Brazelton (Connie Oligario) and CCH Pounder (Angela Hicks). This special episode of Stars in the House will be held in benefit of the Waterkeeper Alliance — the fastest growing global nonprofit focused solely on clean water. For more info: Subscribe to People ►► #StarsInTheHouse #ERReunion #PEOPLE Catch up on the latest celebrity news, top stories and more: PEOPLE goes behind-the-scenes with our cover stars for exclusive stories and in-depth interviews: http