The co-creators, producers, and director of NCIS have spoken about the conflict that led co-creator Donald P. Bellisario to leave the show after 16 years. The conflict arose due to the complexity of the show and difficulties for the actors in figuring out their arcs and lines. Mark Harmon, who played agent Leroy Jethro Gibbs, felt that it was too hard to work this way. Bellisario stepped away from the show by the fifth year, but stated that it was his own decision.

Despite the conflict, Bellisario and Harmon were both instrumental in the success of NCIS.