ABC will air the 300th episode of “Grey’s Anatomy” Thursday, and it’s safe to say that the hospital has gone through some changes. Half of the original cast has moved on to other projects. Catch up with all of your favorite fake doctors below:

Patrick Dempsey: McDreamy officially left Grey Sloan Memorial Hospital in 2015 when Derek Shepard was killed in a car accident.

Dempsey, meanwhile, has been returning to the big screen. He played a big role in “Bridget Jones’s Baby,” and has several movie roles lined up. He’ll star in the romance “Berlin, I Love You” and crime drama “The Postcard Killings” soon.

Dempsey is also set to return to television in a miniseries called “The Truth About Harry Quebert Affair.” He’ll play the title character, a famous writer who is indicted after a girl’s dead body is found on his property. It will air on Epix next year.

Sandra Oh: Cristina Yang left Meredith (Ellen Pompeo) and Seattle behind when she realized that she could never win a Harper Avery there. When Burke (Isaiah Washington) offered her a fancy research facility in Europe in Season 10, she couldn’t say no.

Oh, meanwhile, has been exercising her comedic muscles since leaving the medical drama. She starred alongside Anne Heche in last year’s “Catfight” and Refinery29’s web series “[Expletive] Boyfriends.” She returned to ABC earlier this year for a role on “American Crime,” but she recently signed on for her first series regular role since “Grey’s Anatomy.” She’ll star in BBC America’s “Killing Eve” next year. She’ll play Eve, a bored security services operative who has fantasies about being a spy.

Katherine Heigl: After Izzie Stevens was fired during a hospital merger and Alex (Justin Chambers) refused to get back together with her, she ditched Seattle.

Heigl has worked steadily since leaving the show in 2010, though her more memorable movies were made before her departure. She has tried to return to TV twice with leading roles in “State of Affairs” and “Doubt,” but both shows were canceled after 13 episodes. Her most recent big screen roles were opposite Rosario Dawson in the thriller “Unforgettable” and alongside Alexis Bledel in the LGBT drama “Jenny’s Wedding.” She had a voice role in “The Nut Job 2: Nutty By Nature.”

The actress will step behind the camera to direct a music video for her husband Josh Kelley later this month. The couple currently resides in Utah with their three children. Heigl also runs her lifestyle blog Those Heavenly Days.

T.R. Knight: George O’Malley died after being hit by a bus in 2009, and Knight has thrived on other TV shows since then. He has had memorable arcs on “The Good Wife,” “11.22.63,” “When We Rise” and even returned to Shondaland in “The Catch” earlier this year.

Knight can next be seen in “Hello Again,” a movie adaptation of Michael John LaChiusa’s stage musical. Martha Plimpton, Rumer Willis and Jenna Ushkowitz also star. It hit theaters Wednesday, Nov. 8.

Isaiah Washington: After leaving Cristina at the altar in 2007, Preston Burke actually came back to offer her a job in 2014. Shortly after his brief return to “Grey’s,” Washington started “The 100.” He will return for Season 5 of The CW’s post-apocalyptic drama next year.

Earlier this year, he appeared on the Starz drama “Survivor’s Remorse,” and next year, the actor will star in “Behind the Movement,” a TV movie about how Rosa Parks’ refusal to give up her seat launched civil rights activists into action.

The other original cast members of “Grey’s Anatomy” are still series regulars in the drama’s 14th season. Meredith (Ellen Pompeo), Alex Karev (Justin Chambers), Miranda Bailey (Chandra Wilson) and Richard Webber (James Pickens Jr.) will all appear in the 300th episode, which will honor those who left the series. The landmark episode will feature three patients who remind the doctors of Izzie, George and Cristina.

“Grey’s Anatomy” airs Thursdays at 8 p.m. EDT on ABC.

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