The federal government has had the ability to respond to incidents of national significance for decades. Since 11 September 2001, there have been enhancements to existing federal assets and the creation of new federal assets. This presentation will provide an overview of the more significant federal assets. Pivotal to a response of national significance is the U.S. Department of Energy (DOE) Federal Radiological Monitoring and Assessment Center, which organizes and coordinates federal agency monitoring activities during an emergency. DOE manages the Federal Radiological Monitoring and Assessment Center during the emergency phase, and the Environmental Protection Agency (EPA) manages the response during the recovery phase once the emergency is terminated. EPA monitoring teams provide support during both the emergency and recovery phases of an emergency. Other DOE teams are available to respond to major nuclear power plant events, transportation accidents, or terrorism events involving the use of radiological materials, including the Radiological Assistance Program, the Aerial Measuring System, the National Atmospheric Release Advisory Center, and the Radiation Emergency Assistance Center/Training Site. For incidents involving a nuclear weapon, an improvised nuclear device, or a radiological dispersal device, DOE assets such as the Nuclear Emergency Support Team and the Accident Response Group could provide capabilities for weapon or device search, recovery, and removal. The Radiological Triage System harnesses the weapons scientists and engineers at the DOE national laboratories to provide gamma spectroscopy interpretation for agencies responding to an incident. In recent years, National Guard Weapons of Mass Destruction-Civil Support Teams have been created to support state and local response to terrorism events. The Civil Support Teams normally come under direct control of the state and can respond without requiring authorization from the U.S. Department of Defense (DoD). Changes brought about by the events of September 11 also extend to changing federal response policy and planning. Therefore, the Catastrophic Incident Response Annex to the National Response Plan is discussed. DoD also provides specifically designated radiological response capabilities that can be utilized within the guidelines of the National Response Plan. While optimally designed to support military missions, these resources also help provide for a well-equipped set of national assets to temporarily support and augment the local, state, and federal civil agencies that have primary authority and responsibility for domestic disaster assistance. The military's role in domestic emergencies is well defined in military regulations, as well as the national plan.