NCIS: Los Angeles is an American television series combining elements of the military drama and police procedural genres, which premiered on the CBS network on September 22, 2009. The series follows the exploits of the Los Angeles–based Office of Special Projects (OSP), an elite division of the Naval Criminal Investigative Service that specializes in undercover assignments.
NCIS: Los Angeles is the first spin-off of the successful series NCIS, itself a spin-off of another CBS series, JAG. On October 7, 2009, CBS gave the series a full-season pickup, extending the first season to 22 episodes. The season was extended again on November 4, 2009, when CBS announced its order for an additional two episodes.