Why Did Izzie Leave Grey's Anatomy?

When you think about the fact that "Grey's Anatomy" has been on television since 2005 — setting a record for the longest-running medical procedural of all time in the process — it makes a whole lot of sense that cast members come and go all the time. When it comes to the original cast members, only two people from the show's humble beginning as a mid-season replacement on ABC have stuck around — Chandra Wilson and James Pickens Jr. as Dr. Miranda Bailey and Dr. Richard Webber, respectively. Even Ellen Pompeo, who spent 19 seasons putting the "Grey" in "Grey's Anatomy" as Dr. Meredith Grey, left the show as a series regular in early 2023 (though she still provides voice-overs for the episodes, serves as an executive producer, and appears on the show surprisingly frequently). So what about Katherine Heigl, who played Dr. Isobel "Izzie" Stevens on the series until its sixth season?

There's actually a ton of drama surrounding Heigl's exit from "Grey's Anatomy," most of which centers around some public comments by the actress and an apparent feud with the show's creator and then-showrunner Shonda Rhimes. So how did Izzie leave the show, and did she ever return? (The answers in brief: in a totally messy and abrupt way, and not really but kind of.) Has Heigl talked about "Grey's Anatomy" since she left the series, and what has she been doing since? Here's everything we know about why Izzie Stevens and Katherine Heigl left Grey's Anatomy.

In the fifth season of "Grey's Anatomy," Izzie starts experiencing something ... really strange. Specifically, she starts to hallucinate her dead fiancé and former heart transplant patient Denny Duquette — played by Jeffrey Dean Morgan, who originated the role in Season 2 — and it's not just a hallucination, because the two sleep together. (A lot. Almost constantly, actually. It's bizarre!) At a certain point, Izzie decides maybe she should try and figure out what the hell is going on with her, and as it turns out, she has stage 4 metastatic melanoma, a particularly aggressive form of cancer that's spread to her brain, skin, and liver. Denny, who keeps saying he's "there for her," is being literal — she's dying.

Because this is a TV show and Izzie was a main character at the time, Izzie survives after multiple harrowing surgeries, a rough course of chemotherapy, and the loss of her best friend, fellow surgical resident Dr. George O'Malley (T.R. Knight), going into remission shortly after she marries another surgical resident in her class, Dr. Alex Karev (Justin Chambers). Despite her miraculous recovery, things get way worse for Izzie when the show's central medical facility, Seattle Grace Hospital, merges with the nearby Mercy West, leading to personnel cuts as two resident classes combine and fight it out for spots in the program. 

Izzie, distracted by a Mercy West resident's rudeness, orders a dangerously wrong dosage of medicine for a patient, and get fired ... only to be told during the firing process that Alex expressed concern about her returning to surgery so quickly. Furious at Alex, Izzie leaves a note and vanishes only to return a little while later, hoping to reconcile; a devastated Alex tells Izzie that, while he's happy that all of her scans are clean and her cancer is fully in remission, he never wants to see her again in the Season 6 episode "I Like You So Much Better When You're Naked." This marks Izzie's final appearance on the show — and Heigl's.

To be honest, Katherine Heigl has given a whole host of reasons, throughout the years, to explain her departure from "Grey's Anatomy." Before there was any real talk of her leaving the show, she removed herself from Emmy consideration after winning an award for her performance in Season 2 (more on that shortly), and in 2010, Entertainment Weekly announced, through a statement from Heigl herself, that she and showrunner Shonda Rhimes had come to an agreement and that she — and Izzie Stevens — wouldn't return for any more episodes in Season 6. Still, in Lynette Rice's 2021 book "How to Save a Life: The Inside Story of Grey's Anatomy," Heigl said something different: she left the show for her growing family (in 2009, Heigl adopted a daughter from South Korea). 

"I started a family, and it changed everything for me," Heigl told Rice in the book. "It changed my desire to work full time. I went on family leave and spent three months in Utah and just got to be a mom, and it changed my whole perspective ... that was really the turning point for me. So before I was due back, I spoke again to Shonda about wanting to leave. Then I waited at home until I was given the formal okay that I was off the show. The rumors that I refused to return were totally untrue.

Then, in 2022, Heigl told SiriusXM host Bevy Smith that she was struggling with her mental health and that's why she left the long-running medical drama. After saying she stopped watching the show after she left, Heigl said that she experienced "insanity" on set. "I think with 'Grey's' at that time, I didn't feel I had any other choice [but to leave]," she said. "I was breaking, it was breaking me, and I was young [...] I mean, I was vibrating at a level that I was gonna get sick and, you know, I did get mentally sick."

When Katherine Heigl decided to leave "Grey's Anatomy" in the rearview mirror — no matter what the "real" reason was — there was quite a lot of drama surrounding both the actress and showrunner Shonda Rhimes. Rhimes, for her part, was extremely blunt during an interview with The Hollywood Reporter in 2014; as she discussed the cast of her second major hit "Scandal," Rhimes mentioned a "no a**hole policy" and went so far as to say, "There are no Heigls in this situation [...] I don't put up with bullsh** or nasty people. I don't have time for it."

Heigl responded directly to those remarks speaking to Mario Lopez for Extra that same year and sounded appropriately contrite. "I am sorry that she feels that way and I wish her nothing but greatness and I have nothing negative to say about [her]. I'm a big fan of her work," Heigl said in response to Rhimes' super-viral comment. "I watch 'Scandal' every week and so I'm sorry she's left with such a crappy impression of me. I wish I could do something to change that. Maybe I will be able to someday."

It's safe to say that Heigl's stunt with the Emmys — where, in 2008, she told The New York Times that she "did not feel that [she] was given the material [in Season 4 of 'Grey's Anatomy'] to warrant an Emmy nomination" — is probably what really pissed Rhimes off. To be fair to Heigl, she later said that she regretted the situation. In conversation with Entertainment Weekly in 2021, Heigl admitted that she was unfair to the writers and the show's creative team — and that it was an insensitive approach. "At the time, I thought I was doing the right thing," she said. "I wanted to be clear that I wasn't snubbing the Emmys. The night I won [in 2007] was the highlight of my career. I just was afraid that if I said, 'No comment,' it was going to come off like I couldn't be bothered to [enter the race]. But really, I could have more gracefully said that without going into a private work matter. It was between me and the writers. I ambushed them, and it wasn't very nice or fair."

Katherine Heigl's real corporeal form never returned to "Grey's Anatomy" specifically ... but in Season 16 of the show, her ex-husband Alex Karev leaves his entire life in Seattle behind for an unseen Izzie Stevens and their children. Here's how it all went down. In the sixteenth episode of that season, "Leave a Light On," fans already knew that Justin Chambers was set to leave the series behind, but many of them didn't realize that the actor's actual final appearance took place in the show's 350th episode "My Shot" (a full eight episodes before "Leave a Light On"). When viewers finally learned what exactly happened to Alex — who, at this point in the series, is married to Dr. Jo Wilson (Camilla Luddington) and Meredith Grey's closest remaining confidante — it's an understatement to say they were shocked and gutted by the character's unceremonious sendoff.

In Season 5, the show mentions that Izzie and Alex froze and fertilized embryos before she underwent chemotherapy, and as it turns out, Alex found out — years after the fact — that Izzie usd those embryos to have two children. So, no; Izzie doesn't return, nor does Heigl, but the ghost of Izzie is what removes Alex from the show for good, leaving fans (and Jo and Meredith) surprised and bereft.

After leaving "Grey's Anatomy," Katherine Heigl — who, before leaving the show, starred in big-screen hits like "27 Dresses" and "Knocked Up" — continued working on romantic comedies, but unfortunately, projects like "Killers" and "One for the Money" provided diminishing returns. On the small screen, Heigl worked on the political drama "State of Affairs" from 2014 to 2015 and joined the cast of "Suits" during its eighth and ninth season (from 2018 to 2019), but her biggest post-"Grey's Anatomy" project is definitely "Firefly Lane," a soapy Netflix drama centering around the lifelong friendship of the outgoing Tully Hart (Heigl) and the quiet, meek Kate Mularkey (Sarah Chalke).

Despite her rocky history with the ABC drama, Heigl has found ways to stay involved with the show's story, so to speak. In the summer of 2023, Heigl sat down with her friend and former colleague Ellen Pompeo for an installment of Variety's series Actors on Actors — where the two spilled some very gross secrets about on-screen surgery — and in January of 2024, Heigl joined Pompeo, Chandra Wilson, Justin Chambers, and James Pickens Jr. at the 75th Primetime Emmy Awards to present an award and commemorate their show with a reunion.

"Grey's Anatomy" is streaming on Netflix and Hulu now.