Why NCIS' Co-Creator Left The Show After Four Seasons

Few crime shows can match the longevity of "NCIS," but ironically, series co-creator Donald P. Bellisario didn't stick around for most of its run.

Bellisario and Don McGill premiered "NCIS" in 2003, beginning the show's decades-long run. The Emmy-nominated CBS police procedural has aired over 500 episodes across 23 seasons, revolving around Special Agent Leroy Jethro Gibbs (Mark Harmon) and other investigators as they handle high-stakes military crimes. 

In The Hollywood Reporter's 2023 oral history interview with the "NCIS" creative team, executive producer Charles Floyd Johnson confirmed prior reporting that a conflict with Harmon, who headlined the first 19 seasons of "NCIS," prompted Bellisario's departure after Season 4. 

"Eventually, actors felt like they would get two acts or one act, and they didn't know what their arc was for the show," Johnson said. "They couldn't figure out their lines. It was a very complicated show in the beginning. And so when we got to about year four, Harmon just felt like it was too hard. He never said to anybody, 'Get rid of Don.' He just said, 'This is too hard to work this way.' Eventually, the network went to Bellisario and said, 'Maybe you should work from a distance from it and not be quite as involved in terms of the way you work.' And so Bellisario, by the fifth year, was gone."

Donald P. Bellisario spoke about his exit from "NCIS," offering insight into why it felt like the right choice. "It was just time for me to move on and do something else," he shared. "I had done enough on the show, so I stepped away. It was my decision."

Don McGill worked alongside Bellisario for four years on "NCIS," though, he said he learned of Bellisario's friction with Harmon "in the trades." "I know that Mark was not happy, and that he and Don, their relationship became strained," McGill said. "It's just one of those things that happens, the classic Hollywood creative differences."

Not much about "NCIS" changed after Bellisario left, as Charles Floyd Johnson and fellow executive producer Shane Brennan took over as showrunners. Even so, 16 years after parting ways with Bellisario, Johnson admitted that "without him, there would be no 'NCIS.'"

In the early 2010s, Bellisario thought similarly about "NCIS: Los Angeles" and sued CBS for compensation he claimed the network contractually owed him for the spin-off to his idea. CBS settled with Bellisario out of court in 2013.