The National Response System (NRS) is the government's mechanism for emergency response to discharges of oil and the release of chemicals into the navigable waters or environment of the United States and its territories. Initially, this system focused on oil spills and selected hazardous polluting substances discharged into the environment. It has since been expanded by other legislation to include hazardous substances and wastes released to all types of media.

The NRS functions through a network of interagency and inter-government relationships which were formally established and described in the National Oil and Hazardous Substances Pollution Contingency Plan (NCP). The NCP establishes three high level organizations and four special force components which are described below.

Federal On-Scene Coordinators (FOSC)

The FOSC is a federal official, pre-designated by EPA for inland areas and by the Coast Guard for coastal or major navigable waterways. These individuals coordinate all federal containment, removal, disposal efforts, and resources during an incident. The FOSC also coordinates federal efforts with the local community's response. Anyone responsible for reporting releases should be aware of which FOSC has responsibility for the affected area. For locations near the coast or a major waterway, there may be both a Coast Guard and EPA FOSC with assigned responsibilities within jurisdictional boundaries of various state or local entities.

National Response Team (NRT)

The National Response Team's membership consists of 16 federal agencies with interest and expertise in various aspects of emergency response to pollution incidents. The NRT is a planning, policy, and coordinating body; providing national level policy guidance prior to an incident and does not respond directly to an incident. They can provide assistance to an FOSC during an incident, usually in the form of technical advice or access to additional resources and equipment at the national level.

Regional Response Team (RRT)

The RRT's are the next organizational level in the federal response system. Currently, there are 13 RRTs, one for each of the ten federal regions, plus one each for Alaska, the Caribbean and the Pacific Basin. Each team maintains a Regional Contingency Plan and both the state and federal governments are represented. The RRTs are primarily planning, policy and coordinating bodies. They provide guidance to FOSCs through the Regional Contingency Plans and work to locate assistance requested by the FOSC during an incident. RRTs may also provide assistance to state and local governments in preparing, planning or training for emergency response.

The four special force components are;

Coast Guard National Strike Force (NSF)

 The NSF is composed of three strategically located strike teams and a coordination center. The strike teams have specially trained personnel and are equipped to respond to major oil spills and chemical releases. The coordination center maintains a national inventory listing of spill response equipment and assists with the development and implementation of an exercise and training program for the National Response System. NSF capabilities are especially suited to incidents occurring in the marine environment, but also include site assessments, safety, action plan development and documentation for both inland and coastal zone incidents.

Coast Guard Public Information Assist Team (PIAT)

The PIAT is a highly skilled unit of public affairs specialists prepared to complement the existing public information capabilities of the Federal On-Scene Coordinator.

EPA Environmental Response Team (ERT)

The ERT is a group of specially trained scientists and engineers based in Edison, NJ and Cincinnati, OH. Its capabilities include multimedia sampling and analysis, hazard assessment, cleanup techniques and technical support.

Scientific Support Coordinators (SSC)

The National Oceanic and Atmospheric Administration (NOAA) provides SSC in coastal and marine areas. The SSC serves on the FOSC staff as the lead of a scientific team. This support team provides expertise in environmental chemistry, oil slick tracking, pollutant transport modeling, natural resources at risk, environmental tradeoffs of countermeasures and cleanup, information management, contingency planning and liaison to the scientific community and the natural resource trustees.