In Honor of Grey's Anatomy's 15th Anniversary, Photos of the Original Cast Then & Now

First Episode: Season 1, Episode 1

The titular character of the show, audiences were introduced to Meredith Grey on the morning of her first day as an intern at Seattle Grace hospital. In the first episode of the series, Meredith slept with Derek Shepherd, only to find out that he was not just her coworker, but her superior. 

Latest Episode: Season 16, Episode 18 

Meredith has been through a lot over the years. If you haven't seen the show, it includes the death of her friends, a hospital shooting, a plane crash, the death of her husband, insurance fraud ... the list seems endless. She's had a few love interests since the death of her husband and is mom to three kids. Meredith is still on the show, but only after being fired and doing community service after committing insurance fraud. 

Pompeo originally expressed her desire to leave the show, telling Entertainment Weekly in September 2018, "My children are getting older so I want to be more available to them now. I can’t be an absentee mom if they’re teenagers, I have to be around to whip their butts. So it’s definitely time for change in my life. I’m really looking forward to it and that’s the beauty of my situation. I have definitely played this out for everything that I possibly could. I’ve given it 200 percent of my energy and my love and my time and my commitment and my dedication. I still am fighting every day to make everything surrounding this show, the quality of the show, the storytelling, I’m still fighting for everything I can, for the quality to be good, for the actors to be happy, whether that’s well received or not. I still care very much about the show and I think that it takes a lot of energy. So at some point I have to wrap it up.”

But just one month later, in October 2018, Pompeo told Ellen DeGeneres that she would be staying on for the foreseeable future. She told the host: "And, you know, these numbers — there’s just no end in sight with streaming, and the show is so popular."

She added, "I gotta keep doing it, man, because we’re touching lives and making a difference."

First Episode: Season 1, Episode 1

Dr. Richard Webber was introduced in the first episode of the series as the Chief of Surgery who immediately recognized Meredith's talent and lineage — he worked with her mother, Ellis Grey. 

Latest Episode: Season 16, Episode 18 

Not much has changed in terms of Richard's personality, but he has been through — like everyone else who's been on the show for 16 seasons — a lot. He lost his wife, was electrocuted, developed a dependency on alcohol and lost his job (briefly) after helping Meredith commit insurance fraud.  

First Episode: Season 1, Episode 1

Dr. Bailey was introduced to the world as "The Nazi" for her stern demeanor and refusal to take any nonsense. Deep down, though, she loved and cared for her interns and worked hard to see them succeed. 

Latest Episode: Season 16, Episode 18 

She still doesn't take any crap from anyone, but now Bailey is the Chief of Surgery who doesn't take crap from anyone. That's not to say she hasn't had her own struggles, but throughout the years she has been one of the more stable characters in the series.

In season 15, she fired both Richard and Meredith after an insurance fraud incident, though they have since returned to work under her. Currently, she's still attempting to keep everyone in line. 

First Episode: Season 1, Episode 1

Alex Karev was the cocky, overconfident intern who had the nerve to call Meredith Grey a nurse. 

Last Episode: Season 16, Episode 16

After 15 years of redeeming his character flaws, Karev left his career, friendships and wife behind when he left Seattle Grace for Kansas to reunite with Izzie and *gasp* their twins that Izzie had conceived using frozen embryos. 

Chambers said of his departure, "There’s no good time to say goodbye to a show and character that’s defined so much of my life for the past 15 years. For some time now, however, I have hoped to diversify my acting roles and career choices. And, as I turn 50 and am blessed with my remarkable, supportive wife and five wonderful children, now is that time.”

He added, “As I move on from Grey’s Anatomy, I want to thank the ABC family, Shonda Rimes, original cast members Ellen Pompeo, Chandra Wilson and James Pickens, and the rest of the amazing cast and crew, both past and present, and, of course, the fans for an extraordinary ride."

First Episode: Season 1, Episode 1

Derek Shepherd's nickname says it all. We met Dr. McDreamy after what was supposed to be a one-night stand with Meredith Grey. Their relationship turned into one of the most iconic in television. 

Last Episode: Season 11, Episode 25

In a truly heartbreaking episode, Derek was hit by a car while helping the victims of a crash, and then unable to be saved by a lackluster medical team at another hospital. To make it worse, the viewer got to hear Shepherd's thought process through it all, and know that he knew what medical attention he needed. It was just too much. 

Fans felt that the character death was unfair, but creator Shonda Rhimes stood by it as her only option: "Meredith and Derek's love had to remain Meredith and Derek's love," Rhimes said. "As painful as it was for me as a storyteller, because I had never really thought that was going to happen, it preserved what felt true to me, was that Derek was going to have to die in order for that love to remain honest. Because I really couldn't have the idea that he just turned out to be a bad guy who walked out on his wife and kids be a true story. To me, it felt like that was the only way to make Meredith and Derek's magic remain true and forever frozen in time."

Dempsey told PEOPLE, "“I’m very grateful for Grey’s Anatomy. It’s given me the opportunity to do everything. But at the same time, there was a cost.”

“I think after a certain period of time, no matter how much money you make, you want control out of your own schedule,” the actor said of the decision. 

“It had been long enough. It was time for me to move on with other things and other interests. I probably should have moved on a couple of years earlier. I stayed a bit longer than I should have.”

First Episode: Season 2, Episode 19 

Our first glimpse of Callie Torres was as a badass surgical resident who fixed George O'Malley's dislocated shoulder. 

Last Episode: Season 12, episode 24

After 10 seasons on the series and a whole lot of drama between Callie and her ex-wife, Arizona Robbins, they finally agree that Torres should move to New York City in order to be happy. 

Ramirez said in a Twitter statement about her departure,  “I’m deeply grateful to have spent the last 10 years with my family at Grey’s Anatomy and ABC, but for now, I’m taking some welcome time off. Shonda’s been so incredible to work for and we will definitely continue our conversations! I send my love to Ellen [Pompeo], the rest of the cast and crew, and I look forward to always being a part of the Shondaland family!”

First Episode: Season 1, Episode 1

Cristina Yang was the headstrong, super-smart, no-nonsense intern who'd do just about anything to succeed. She also quickly became Meredith's best friend. 

Last Episode: Season 10, Episode 24 

Yang left Grey Sloan Memorial Hospital — this was after they renamed the hospital (again) — for the Klausman Institute for Medical Research in Switzerland. She has been mentioned on the show since, usually in regards to phone calls, e-mails or letters. 

When she left the show in 2014, Oh told The Hollywood Reporter that she was open to returning when the series ends. "I told [Shonda], "If you guys want to finish it out however you want to finish it out, I'd be more than happy to come back. And if it doesn't fit in that way, I totally understand. I just want you to know that I'm available. Who knows! I might be doing something fabulous and it might not work out but I did say, 'Yes, of course I would.' "

First Episode: Season 2, Episode 18 

Dubbed Dr. McSteamy, Mark Sloan came onto the scene and was immediately punched in the face by McDreamy for hitting on Meredith (after sleeping with Derek's ex-wife). Not a fantastic start by any means. 

Last Episode: Season 9, Episode 2 

He seemingly survived the plane crash that killed his love interest, tricked us all into thinking he would survive when he had what the doctors called "The Surge," a.k.a. one last burst of energy before dying, and then had to be pulled off of life support. It was another brutal blow. 

The actor reportedly left the show after being offered a role on the show The Last Ship. Dane told Entertainment Weekly, "Grey’s Anatomy is a world — it’s not about any one individual actor and the storylines were sort of … you know, heading in different directions. So it was an opportunity for me to go and I was interested in something different. I loved doing Grey’s Anatomy. I would have done it until the final episode, but this was something I couldn’t pass up.”

First Episode: Season 3, Episode 24 

Bright-eyed and ready to save some lives, Lexie Grey started as an intern at Seattle Grace in the show's third season. She's the half-sister of Meredith, which came as a shock to, well, everyone. 

Last Episode: Season 8, Episode 24

After finally finding love with Mark Sloan, Lexie's death hit viewers hard. She died in the plane crash that ended the eighth season of the show, leaving everyone (but especially Mark) heartbroken. 

The actress told TVLine at the time, "Earlier this year, I made the decision that season eight would be my last on Grey’s Anatomy. I met with Shonda and we worked together to give Lexie’s story appropriate closure. I am very lucky to have worked with this amazing cast and crew for five seasons. My experience on Grey’s Anatomy is something that I will treasure for the rest of my life. I want to take this time to say thank you to the fans. Your unconditional love and support have made these last five years very special for me. I look forward to my next chapter and I hope you will continue to follow me on my journey.”

First Episode: Season 1, Episode 1

Izzie Stevens started the series as the intern who grew up in a trailer park with her mother, and paid her way through medical school by modeling. She was kind and trusting and loved to bake, which made her the perfect antithesis for the dark and twisty Meredith and Cristina. 

Last Episode: Season 6, Episode 12

It was a rough ride for Izzie who, in season two, fell in love with a patient, Denny Duquette, who needed a heart transplant, risked her career to get him one, and then had to cope with his death. She also developed brain cancer, which made her hallucinate that Denny was a ghost. She had a few on-and-off relationships and eventually married Alex Karev, but it was all short-lived as she found herself fired from Seattle Grace as it was merged with Mercy West hospital in season six. She made one last attempt to return to the hospital, but eventually Karev told her to leave, ending her time on the series. 

While viewers didn't get to see her again, she was mentioned as the reason Karev left the hospital in the show's 16th season to be with her and their twins. 

The real-life story behind Heigl's departure is about as rocky.

It all started when Heigl withdrew her name from Emmy nominations in 2008, which didn't exactly keep her in good graces with the show's creator and producers. She reportedly said at the time: "I did not feel that I was given the material this season to warrant an Emmy nomination and in an effort to maintain the integrity of the academy organization, I withdrew my name from contention. In addition, I did not want to potentially take away an opportunity from an actress who was given such materials.". 

In 2010, Shonda Rhimes told Oprah Winfrey of Heigl's move, "On some level, it stung and on some level I was not surprised. When people show you who they are, believe them."

Heigl told Howard Stern that she did apologize to Rhimes, saying, "I went in to Shonda and said, ‘I’m so sorry. That wasn’t cool, and I should not have said that.’ And I shouldn’t have said anything publicly. But at the time, I didn’t think anyone would notice … I just quietly didn’t submit and then it became a story, and I felt I was obligated to make my statement, and … ‘Shut up, Katie.'”

First Episode: Season 1, Episode 1

Aside from being the first intern to perform an appendectomy (and being dubbed 007 because he had a license to kill) George O'Malley was an overeager, kind-hearted intern who was totally in love with Meredith. 

Last Episode: Season 6, Episode 1

Who could forget finding out that George O'Malley was the badly injured, unrecognizable patient who saved a woman from an oncoming bus? It was truly one of the more brutal character deaths on Grey's. 

Knight left the show after five seasons for a few reasons, citing lack of screen time, his character's storyline and “breakdown of communication” between himself and Rhimes to Entertainment Weekly in 2009. 

“My five-year experience proved to me that I could not trust any answer that was given [about George],” he told the magazine. 

First Episode: Season 1, Episode 1

The talented cardiothoracic surgeon was first introduced as, yes, extremely good-looking and brilliant, but also made a mark as being tough on George O'Malley to set an example for the other interns. 

Last Episode: Season 3, Episode 25 

Burke left the series after leaving Cristina Yang at the altar. In reality, Washington was let go from the show because of an incident in which he called castmate T.R. Knight a homophobic slur. He did return for one episode in Season 10, to urge Cristina to leave Washington to take over his hospital in Switzerland. 

First Episode: Season 1, Episode 9 

When we first met Addison Montgomery Shepherd, she was showing up at Seattle Grace to save her marriage to Derek. She had cheated on him with their friend, Mark Sloan, and wanted to make amends ... just as Derek and Meredith were starting to get close. 

Last Episode: Season 3, Episode 25 

After losing out on a second chance with Derek and missing out on getting a job at Seattle Grace, Addison cut her losses and left. On the bright side, she did get her own spin-off, Private Practice, which ran for six seasons.