The primary prohibition on material support of terrorism is in the Anti-Terrorism and Effective Death Penalty Act (AEDPA), which prohibits material support to Foreign Terrorist Organizations (FTOs) designated by the Secretary of State.
In addition to the FTO list, the material support prohibition also applies to a broader list of terrorist entities and individuals designated by the Department of Treasury under sanctions laws, primarily the International Emergency Economic Powers Act (IEEPA). Executive Orders issued under authority of various sanctions statutes have also included a prohibition on providing material support, without defining it. In the absence of a definition, the AEDPA definition is generally referred to for sanctions compliance purposes.
* Individuals and groups on this list, along with individuals and entities listed under various U.S. sanctions programs, narcotics traffickers, money launderers, etc., are collectively referred to as Specially Designated Nationals (SDNs). Treasury maintains a searchable database of all SDNs at https://www.treasury.gov/resource-center/sanctions/SDN-List/Pages/default.aspx
Helpful information on terrorist designations, their legal authority and the prohibitions they create, can be found on the State Department’s website at www.state.gov/terrorism-designations-faqs/.