Although NCIS is now closely tied to CBS, its early rise was helped by an unexpected partner. After their third seasons, both JAG and NCIS were picked up by USA Network, where constant reruns introduced the shows to new audiences long before streaming took off.
Executive producer Mark Horowitz has credited those marathon airings with helping NCIS climb to the No. 1 spot, a view shared by creator Donald P. Bellisario, who said he was surprised by how quickly the series gained momentum. Mark Harmon, who played Leroy Jethro Gibbs for nearly two decades, has also spoken about the demanding early years, noting the show built its success through steady persistence rather than instant fame.
Now more than 20 seasons in, with several spin-offs to its name, NCIS remains a pillar of network television.