Is Mark Harmon leaving the NCIS cast this season? Tue May 04, 2021 at 8:37pm ET Questions about whether or not Mark Harmon is leaving the NCIS cast this season continue to persist. Quite a few recent storylines have helped push the rumors that Harmon is ready to leave the show. Plus, when Gibbs got suspended, it caused a lot of fans to think about what the show might look like if Harmon did decide to move on to other things. NCIS was just renewed for Season 19, which means that CBS feels confident that the drama can do well in the 2021-2022 television season. The network may also know the level of involvement that Harmon plans to have, even if that information has not yet been made public.