Mark Harmon: I'll leave NCIS when the writers can't come up with anymore storylines

People

The actor, who's spent 16 years playing Gibbs on the CBS drama, tells People: “I’ve always thought if there’s ever a time where the writers are walking into the room and going ‘I don’t know what to do,’ then I think we all have to look at each other and call it a day. But we’re not there yet.”