TVLine's Matt Webb Mitovich reports, with NCIS's eleventh season due to start production next week, Cote de Pablo (Ziva David) has announced she is leaving the show. de Pablo's contract expired last season, but she will appear at the start of Season 11 to wrap up Ziva's arc.
Several characters have left NCIS over the years, but not a character this important, a field agent, since Kate Todd was killed by Ari Haswari and replaced by Ziva. That change succeeded, in part because Kate and Ziva were very different characters fleshed out over time. I'd like to see a new female field agent added to maintain the show's overall appeal, but things could go in another direction.