The FDA is an agency within the United States Department of Health and Human Services responsible for protecting and promoting the nation's public health. The FDA is headquartered in Rockville, MD with 223 field offices[2] supported by 13 laboratories located throughout the United States, the U.S. Virgin Islands, and Puerto Rico. In recent years the agency began undertaking a large-scale effort to consolidate its DC-metro area operations from its main headquarters in Rockville and several fragmented office buildings in the vicinity to the former site of the Naval Ordnance Laboratory in the White Oak area of Silver Spring, MD. The first building, a Life Sciences Laboratory, was dedicated and opened with 104 employees on the campus in December 2003. The project is slated to be completed by 2013.

The agency is organized into the following major subdivisions, each focused on a major area of regulatory responsibility:

1. The Office of the Commissioner (OC)
2. The Center for Drug Evaluation and Research (CDER)
3. The Center for Biologics Evaluation and Research (CBER)
4. The Center for Food Safety and Applied Nutrition (CFSAN)
5. The Center for Devices and Radiological Health (CDRH)
6. The Center for Veterinary Medicine (CVM)
7. The National Center for Toxicological Research (NCTR)
8. The Office of Regulatory Affairs (ORA)
9. The Office of Criminal Investigations (OCI)
   

While all of the Centers are located around the Washington, D.C., area as part of the Headquarters divisions, ORA and OCI are primarily field offices, with their workforce spread across the country. ORA is considered the "eyes and ears" of the agency, conducting the vast majority of the field work the Agency. Consumer Safety Officers, more commonly called Investigators, are the individuals who inspect production and warehousing facilities, investigate complaints, illnesses, or outbreaks, and review documentation in the case of medical devices, drugs, biological products, and other items where it may be difficult to conduct a physical examination or take a physical sample of the product. The Office of Regulatory Affairs is divided into five regions, which are further divided into 13 districts. Districts are based roughly on the geographic divisions of the Judicial System. Each district comprises a main district office, and a number of Resident Posts, which are FDA offices located away from the district office to serve a particular geographic area. ORA also includes the Agency's network of laboratories, which analyze any physical samples taken. Though samples are usually food-related, some laboratories are equipped to analyze drugs, cosmetics, and radiation-emitting devices.

OCI was established in 2002 to help relieve ORA of the burden of pursuing and proving criminal cases. Unlike ORA Investigators, OCI Special Agents are armed, and are not focused on the technical aspects of whether a regulated product meets the standards under the law. Rather, OCI agents pursue and develop cases where criminal actions have occurred, such as fraudulent claims, or knowingly and willfully shipping known adulterated goods in interstate commerce. In many cases, OCI will pursue cases where Title 18 (18 USC XXXX) violations have occurred (e.g. conspiracy, false statements, wire fraud, mail fraud), in addition to prohibited acts as defined in Chapter III of the FD&C Act (21 USC XXX). OCI Special Agents often come from other criminal investigations backgrounds, and work closely with the FBI, US Assistant Attorney Generals, and even Interpol. OCI will receive cases from a variety of sources, including ORA, local agencies, and the FBI, and will work with ORA investigators to help develop the technical and science-based aspects of a case. OCI is a much smaller branch, comprising of about 200 agents nationwide.

The FDA frequently works in conjunction with other Federal agencies including the Department of Agriculture, Drug Enforcement Administration, Customs and Border Protection, and Consumer Product Safety Commission. Often local and state government agencies also work in cooperation with the FDA to provide regulatory inspections and enforcement action.