At the end of Monday's (11Oct21) episode, titled "Great Wide Open", Harmon's character announces [SPOILER ALERT!] he's staying in Alaska after solving his final case.
In a statement, NCIS executive producer and showrunner Steve Binder praised Harmon, who has fronted the series for 18 years.
"As an executive producer and dear friend, Mark continues to be an integral part of the fabric of the show," Binder said. "Our north star has always been staying true to our characters, and that truth has always guided the stories we tell and where those characters go. So regarding the future of Gibbs, as long-time fans of the show may have noticed over the years... never count Leroy Jethro Gibbs out."
It's not yet clear if Harmon will ever return to NCIS in a guest capacity, but CBS Entertainment president Kelly Kahl says, "Mark's always been part of the show, Mark's always going to be part of the show. In terms of his on-air appearances, we're just going to have to see how it plays out going forward."
Mark Harmon became the second "NCIS" favorite to leave the show in a year. Co-star Emily Wickersham previously departed after season 18 concluded.
"This business is finicky and weird and consistency is a rarity. I've been lucky enough to be a part of a show where I got to show up and act and laugh and learn with wonderful people. A moment in time I surely won't forget," she said back then.