Pauley Perrette is leaving NCIS at the end of the drama's current season, the actress announced Wednesday morning in a tweet. 

She confirmed rumors that she is departing the long-running CBS series after 15 seasons, explaining that it was a decision made last year and "not due to a nonexistent skin-care line or rift" with the network or her castmates.

"I hope everyone will love and enjoy EVERYTHING ABBY not only for the rest of this season but for everything she has given all of us for 16 years," Perrette wrote. "All the love, all the laughter, all the inspiration…. I love her as much as you do."

Perrette has played forensic specialist Abby Sciuto on the series since its 2003 debut. She is one of only three remaining original castmembers, including star and executive producer Mark Harmon and David McCallum. (Sean Murray recurred in the first season of the procedural and was promoted to series regular for season two.)

"Pauley has been a valued member of both NCIS and the CBS Family for over 15 years," CBS and CBS Television Studios said in a statement. "While it's never easy saying goodbye to a beloved actress and character, we respect her decision to leave at the end of the season. We are grateful to Pauley for all her contributions to the series and making Abby one of the most unique characters on TV."

While NCIS saw some cast changes early in its run (the departures of Sasha Alexander and Lauren Holly), the core cast remained largely unchanged until Cote de Pablo exited the series in 2013. Michael Weatherly followed three years later when he left to star on his own CBS drama, Bull, which now airs after NCIS on Tuesdays. Recent additions to the cast include Wilmer Valderrama, Duane Henry and Maria Bello.

NCIS also saw a major change behind the scenes last year with the sudden death of longtime showrunner Gary Glasberg.

“We’ve known for some time this would be Pauley’s final season on NCIS and have been working toward a special send-off," added NCIS executive producers George Schenck and Frank Cardea. "From day one, she has brought incredible passion and specificity to the role. Abby is a character that inspires millions of fans around the world, and all of us at NCIS are appreciative of Pauley for portraying her.”

NCIS remains an important franchise for CBS, with the continued success of NCIS: Los Angeles. and NCIS: New Orleans. NCIS, itself a spinoff of JAG, also continues to perform well in repeats on USA Network.

The drama just kicked off its 15th season, which is part of a two-season renewal handed out by CBS in 2016 shortly after the network and its CBS TV Studios counterpart renewed Harmon's overall deal, ensuring his continued presence on the series.

Perrette's credits include Almost Famous and The Ring. She is repped by SBD Partners.

Oct. 4, 11:10 a.m. Updated with statements from CBS, CBS TV Studios and NCIS executive producers.