A terrorism endorsement is a provision attached to an insurance policy that restricts, excludes, or otherwise explains coverage for loss due to terrorist acts.
The passage of the Terrorism Risk Insurance Act (TRIA) of 2002 voided all terrorism exclusion endorsements then in force on commercial property and casualty policies, to the extent that such exclusions eliminated coverage for certified acts of terrorism as covered by the federal program. It also led to the creation of many standard terrorism endorsements that provide for a wide range of terrorism coverage options: from no terrorism coverage at all (permissible only when the insured rejects or fails to pay for TRIA terrorism coverage) to full coverage for both international and domestic terrorism, subject to the $100 billion program-year cap established in the Act.