See the 'Grey's Anatomy' cast then and now

The 'Grey's Anatomy' cast is returning for season 20! Join EW as we look back on the series' biggest stars throughout the years, including Ellen Pompeo, Patrick Dempsey, and more.

Grey's Anatomy Is Officially 15 Years Old — Here Are 25 Side-By-Sides Of The Cast Then Vs. Now

See How the 'Grey's Anatomy' Cast Has Changed Since Their First Seasons (PHOTOS)

Grey's Anatomy Cast From Season 1 to Now, How They've Changed

Grey's Anatomy Is Officially 15 Years Old — Here Are 25 Side-By-Sides Of The Cast Then Vs. Now

Grey's Anatomy' Stars: Then and Now

See the 'Grey's Anatomy' Cast Then and Now! Greys anatomy cast, Greys anatomy, Patrick dempsey

Grey's Anatomy' Cast on Their First Episode Vs. Last

Grey's Anatomy' Cast Then & Now: See Ellen Pompeo, Patrick Dempsey & More After 15 Years

Grey's Anatomy' Cast Transformations: Photos – Hollywood Life

Grey's Anatomy Cast: Then And Now