1. Chemical - Composed of four main segments, based on end product: basic chemicals, special chemicals, life sciences, and consumer products.

2. Commercial Facilities - Operate on the principle of open public access, meaning that the general public can move freely throughout these facilities without the deterrent of highly visible security barriers. The majority of the facilities in this sector are owned and operated by the private sector, with minimal interaction with the federal government and other regulatory agencies. (eg. malls, arenas, etc.)

3. Communications - Industries that use terrestrial, satellite, and wireless transmission systems to provide communication abilities to the user.

4. Critical Manufacturing - Consists of four broad manufacturing industries: primary metal manufacturing; machinery manufacturing; electrical equipment; appliance and component manufacturing; and transportation equipment manufacturing. Critical Manufacturing facilities include, but are not limited to, iron and steel mills, aluminum production, engine and transmission production, and motor vehicle, aerospace, and railroad rolling stock manufacturing.

5. Dams - Encompasses major infrastructure assets that harness the water resources of the nation and enable water management, balancing droughts and floods throughout the U.S.

6. Defense Industrial Base - Includes government agencies and the private sector worldwide industrial complex that have capabilities to perform research and development, design, production and maintenance of military weapons systems, subsystems, components or parts to meet military requirements.

7. Emergency Services - Representative of the following first-responder disciplines: emergency management, emergency medical services, fire, hazardous material, law enforcement, bomb squads, tactical operations/special weapons assault teams, and search and rescue.

8. Energy - Composed of the producers and provides of these three interrelated segments: electricity, petroleum, and natural gas.

9. Financial Services - Is composed of banks and institutions that allow users to deposit funds and make payments to other parties or invest funds for both long and short periods, provide credit and liquidity to customers and transfer financial risks among customers.

10. Food and Agriculture - Has the capacity to feed and clothe people well beyond the boundaries of the nation. This sector accounts for roughly one-fifth of the nation's economic activity and is overseen at the federal level by the U.S. Department of Agriculture and the Department of Health and Human Services' Food and Drug Administration.

11. Government Facilities - Includes a wide variety of buildings, owned or leased by federal, state, territorial, local or tribal governments, located domestically and overseas. This includes general-use office buildings and special-use military installations, embassies, courthouses, national laboratories, and structures that may house critical equipment and systems, networks and functions.

12. Information Technology - Comprised of, but not limited to, the following: Domain Name System root and Generic Top-Level Domain operators, internet service providers, internet backbone providers, internet portal and email providers, networking hardward companies, networking software companies, and security service vendors.

13. Nuclear Reactors, Materials and Waste - Includes nuclear power plants; non-power nuclear reactors used for research, testing and training; nuclear materials used in medical, industrial, and academic settings; nuclear fuel fabrication facilities, decommissioning reactors; and the transportation, storage, and disposal of nuclear materials and waste.

14. Healthcare and Public Health - Comprised of hospitals, clinics, and other care facilities dedicated toward the improvement of the health of their customers. The Public Health and Healthcare sector plays a significant role in response and recovery across all other sectors in the even of a natural or manmade disaster.

15. Transportation Systems - Consists of six key subsectors, or modes: aviation, highways, maritime transit, mass transit, pipelines, and rail.

16. Water and Wastewater Systems- Vulnerable to a variety of attacks through contamination with deadly agents, physical attacks such as the release of toxic gaseous chemicals and cyber attacks.