FBI Counterterrorism Division

The Counterterrorism Division (CTD) is a division of the National Security Branch of the Federal Bureau of Investigation. CTD investigates terrorist threats inside the United States, provides information on terrorists outside the country, and tracks known terrorists worldwide. In the wake of the September 11 attacks in 2001, CTD's funding and manpower have significantly increased.

The Division employs counterterrorism field operations organized into squads, the number of which varies according to the amount and diversity of activity in the local field office's jurisdiction. Larger field offices, such as Los Angeles, maintain counterterrorism squads for each major terrorist group, as well as for domestic terrorism and terrorist financing, while smaller field offices combined such responsibilities across two to three squads.