is a fictional character from the medical drama television series Grey's Anatomy, which airs on the American Broadcasting Company (ABC) in the United States.

Introduced as a surgical intern at the fictional Seattle Grace Hospital, Izzie worked her way up to resident level, while her relationships with her colleagues Meredith Grey (Ellen Pompeo), Cristina Yang (Sandra Oh), Alex Karev (Justin Chambers) and George O'Malley (T. R. Knight) formed a focal point of the series.

Heigl made her final series regular appearance as Izzie in the sixth season, leaving Seattle after Alex refused to resume their marriage.

[9] After snooping through her file, Lexie Grey (Chyler Leigh) also discovers Stevens attended night school for college and consequently took six years to finish her undergraduate degree.

[10] Izzie is introduced as a 25-year-old former model in the first episode of Grey's Anatomy, meeting fellow surgical interns Meredith, Cristina, Alex, and George.

When Denny's condition deteriorates, Izzie deliberately worsens his health further by cutting his LVAD wire to move him up the UNOS donor register.

[24] The fourth season premiere "A Change Is Gonna Come" sees 28-year-old Stevens and her peers, except George, promoted to second-year residents.

[44] She also once expressed interest in a potential spin-off for her character Izzie when Kate Walsh's Addison Montgomery left Grey's Anatomy to star in Private Practice.

[45] In 2008, Heigl declined to submit her name for consideration for a Primetime Emmy Award for her work in Grey's Anatomy's fourth season, stating that she felt the material she was given did not warrant a nomination.

[53] Heigl's exit was strategically timed to coincide with lead actress Ellen Pompeo’s maternity leave and shortly after T. R. Knight's departure from the series.

[53] While Pompeo's titular character, Meredith Grey, was given reduced screentime with some scenes filmed in advance for future episodes, Izzie received a purposeful exit storyline.

[54] It was later revealed that her leave would be three months long, and Rhimes confirmed that Heigl would not shoot scenes in advance for her character as Pompeo did for Meredith Grey.

[48] However, after months of ongoing negotiations between Heigl and ABC, both sides mutually agreed to part ways earlier than originally planned, which was publicly announced on March 11, 2010.

[57] Heigl had been in discussions with showrunner Shonda Rhimes about her departure and waited at home in Utah until she was given formal confirmation that she would no longer be part of the series.

[48] Heigl requested to be released from her contract 18 months early and to make her final appearance retroactively in the twelfth episode of the sixth season, "I Like You So Much Better When You're Naked", which aired on January 21, 2010.

[57] In 2020, Grey's Anatomy head writer Krista Vernoff revealed that she had written a farewell episode centered on Izzie, but it was canceled after the production received news that Heigl would not return to complete the arc.

[60][48] On March 24, 2010, Heigl confirmed that her decision to leave the show was due to a shift in her personal priorities, as she wanted to spend more time with her adoptive child and no longer desired to work full-time.

By the nineteenth episode, "Sympathy for the Parents", Heigl's name was officially removed from the main cast, and Kim Raver, who played Dr. Teddy Altman, was added as a series regular following her promotion in January 2010.

"[64] In the How to Save a Life: The Inside Story of Grey's Anatomy (2021) book, former writer Jenna Bans stated that Izzie was kept alive because "Shonda [Rhimes] felt like that was more of an unexpected way to go.

I spent six years together with these people every day... you grow up together, in a way," and again commented on Izzie's possibly returning to the show, "I always felt that if they wanted me to come back and sort of wrap up that storyline...

[70] Initially, Vernoff pitched to Rhimes (who still had executive producer privileges) an original main cast member from the pilot returning as the focal point storyline for the episode after noticing the Izzie lookalike actress, Eryn Rea (who was a Meredith stand-in) through the camera during the early-fourteenth season scenes shot in Seattle.

[71] In 2020, showrunner Krista Vernoff discussed the possibility of Chambers and Heigl returning together after the former's off-screen departure stating, "When I left the show in season 6, people asked me if there was any chance of me ever coming back.

[74] Heigl explained that the fifth episode of Season 2, "Bring the Pain", was pivotal for Izzie's character development, marking her transformation from being vulnerable and underestimated in the pilot to removing her "heart from her sleeve".

Rhimes loved how Izzie subtly "tortures" Callie about washing her hands afterward, capturing the small, humorous interactions that reflect everyday social dynamics.

"[81] Rhimes discussed costuming choices in the scene which saw the interns gather around Denny's deathbed, explaining: "Meredith, George, Cristina, Callie and Alex are all dressed, not for a prom, but for a funeral.

He commended her for handling the intense storylines given to her by showrunner Shonda Rhimes but also pointed out that "there are times when Izzie becomes completely irrational during crisis situations, which may bother some.

"[85] Eyder Peralta of The Houston Chronicle was highly critical of Izzie's decision to cut Denny's LVAD wire in Season 2, deeming it unethical.

Rorke appreciated the depth Izzie's character had developed, stating that she seemed like "the only adult intern" at Seattle Grace, aside from Dr. Miranda Bailey, played by Chandra Wilson.

Otis Brawley, chief medical officer at the American Cancer Society, critiqued the storyline for its unrealistic depiction of treatment options.

Specifically, he pointed out that Izzie's use of interleukin-2 as a treatment for metastatic melanoma with brain involvement was not medically accurate, as the drug is known to cause complications like bleeding and strokes in such cases.