The 39-year-old actress shared her excitement about her return to the ABC drama as character Eva Vasquez in an Instagram post on Wednesday.
"Excited to be back on @station19 stirring up trouble!" Thiebaud wrote.
The actress will end her role as Dr. Britt Westbourne on General Hospital in November, a part which she first began playing in 2012 and recently won an Emmy Award for earlier this year. There's no word yet on how her character will be written out.
Thiebaud will return for Station 19's sixth season, which premieres Oct. 6. In a teaser, the network said, per Deadline: "Misery loves company and Eva finds solace with someone from her past."
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Back in January, ABC announced that the Grey's Anatomy spinoff series was renewed for a sixth season. Krista Vernoff, the show's executive producer and showrunner, will continue her duties for the upcoming season.
"It's a privilege to tell stories of our heroic first responders, who on our show and in real life put their lives on the line every day to keep us all safe," Vernoff, 50, said in a prior statement. "I'm so grateful to Disney and ABC for the early pickup for season six of Station 19!"
"It's a tribute to the incredible work of our talented cast, crew, writers and creative team, as well as the dedication of our loyal fans who tune in every week," she added.
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Kevin Winter/Getty Kelly Thiebaud
The renewal of Station 19 comes after ABC revealed it ordered a 19th season of Grey's Anatomy. According to Craig Erwich, president of Hulu Originals and ABC Entertainment, the two series renewals "ensures more crossover opportunities and a thrilling night of appointment television."
"The riveting storytelling and passionate fan base that Station 19 continues to cultivate is a testament to the unrelenting dedication of Krista Vernoff and the incredibly talented cast and crew," Erwich added of Station 19, specifically.
The series, created by Stacy McKee, premiered on ABC in 2018. The action-drama follows the daily lives of those working at firehouse station 19 in Seattle, Washington.
Jaina Lee Ortiz, Jason George, Grey Damon, Barrett Doss, Jay Hayden, Okieriete Onaodowan, Danielle Savre, Boris Kodjoe, Stefania Spampinato and Carlos Miranda are among some of the stars who make up the series' cast.