Grey's Anatomy is an American television medical drama that premiered on the American Broadcasting Company (ABC), as a mid-season replacement on March 27, 2005. The series has aired eight seasons, and focuses on the fictional lives of surgical interns and residents, as they gradually evolve into seasoned doctors, while trying to maintain personal lives. The show's premise originated with Shonda Rhimes, who serves as an executive producer, along with Betsy Beers, Mark Gordon, Krista Vernoff, Rob Corn, Mark Wilding and Allan Heinberg. The series was created to be racially diverse, utlising a colour-blind casting technique. It is primarily filmed in Los Angeles, California.
The series' protagonist is Dr. Meredith Grey (Ellen Pompeo), who originally is accepted into the residency program at the fictional Seattle Grace Mercy West Hospital. Meredith is assigned to work under Dr. Miranda Bailey (Chandra Wilson), along with Dr. Cristina Yang (Sandra Oh), Dr. George O'Malley (T.R. Knight), Dr. Izzie Stevens (Katherine Heigl) and Dr. Alex Karev (Justin Chambers). Following O'Malley's death and Stevens' departure, they are replaced by Dr. Jackson Avery (Jesse Williams) and Dr. April Kepner (Sarah Drew) in the sixth season. The surgical wing is primitively supervised by Dr. Richard Webber (James Pickens, Jr.), who is eventually replaced by Dr. Derek Shepherd (Patrick Dempsey), and later Dr. Owen Hunt (Kevin McKidd).
Dr. Preston Burke (Isaiah Washington) departs at the conclusion of the third season, and is replaced by Dr. Erica Hahn (Brooke Smith), who leaves the show during the fifth season, and later Dr. Teddy Altman (Kim Raver), who departs at the end of the eighth season. Introduced in the second season is Dr. Addison Montgomery (Kate Walsh), who leaves the show at the end of the third season, in order to launch her own spin-off Private Practice. Dr. Callie Torres (Sara Ramirez) and Dr. Mark Sloan (Eric Dane) also enter the show in the second season, while half sister of Meredith, Dr. Lexie Grey (Chyler Leigh), first appears in season three and dies at the end of season eight. Dr. Arizona Robbins (Jessica Capshaw) is given series regular status at the beginning of the sixth season.
Considered an impact on culture, Grey's Anatomy was among the top-ten rated shows in the United States from its first through fourth seasons. The series has recieved numerous awards, and has also been included in various critics' top ten lists. The show has produced several specials and a musical episode, as well as distributed all seasons to DVD, and released a collection of merchandise. In 2011, Grey's Anatomy was named the fourth-highest revenue earning show, in terms of advertising per half-hour. On May 11, 2012, the series was renewed for a twenty-four episode ninth season, which is scheduled to premiere on September 27.