Guide to Major Federal Agencies

The federal government of the United States operates through hundreds of agencies, departments, commissions, and boards that collectively employ approximately 2.95 million civilian workers and administer programs affecting virtually every aspect of American life. These entities range from cabinet-level departments headed by secretaries who serve in the presidential line of succession to small independent commissions with narrowly defined regulatory mandates. Understanding which agencies exist, what they do, how they are structured, and how citizens interact with them is essential civic knowledge. This page provides an overview of the most significant federal agencies organized by function, their legal authorities, and their practical impact on citizens.

How Federal Agencies Are Created and Governed

Federal agencies are created by Congress through enabling statutes — laws that establish the agency, define its mission, and grant it specific regulatory and enforcement authorities. The agency's enabling statute is its constitutional foundation; the agency cannot act beyond the powers that Congress has delegated to it. When an agency exceeds its statutory authority, its actions are subject to challenge in federal court under the Administrative Procedure Act (APA), 5 U.S.C. § 551-559.

Agencies fall into several organizational categories:

• Cabinet departments — The 15 executive departments whose heads serve in the President's cabinet and are appointed by the President with Senate confirmation. The President can remove cabinet secretaries at will.
• Independent agencies — Agencies that operate outside the cabinet department structure and whose leaders typically serve fixed terms and can only be removed for cause (e.g., the Environmental Protection Agency, the National Aeronautics and Space Administration).
• Independent regulatory commissions — Multi-member bodies with quasi-legislative (rulemaking) and quasi-judicial (adjudication) powers, whose commissioners serve staggered fixed terms to insulate them from direct political control (e.g., the Federal Trade Commission, the Securities and Exchange Commission, the Federal Communications Commission).
• Government corporations — Federally chartered entities that perform commercial functions (e.g., the United States Postal Service, Amtrak, the Tennessee Valley Authority).

All agencies that engage in rulemaking are generally subject to the APA's notice-and-comment requirements: the agency publishes a proposed rule in the Federal Register, accepts public comments for a specified period (typically 30 to 60 days), and then issues a final rule with a statement of basis and purpose that addresses significant comments received.

Public Health and Safety Agencies

Food and Drug Administration (FDA) — An agency within the Department of Health and Human Services, the FDA regulates the safety and efficacy of food products, pharmaceuticals, medical devices, biologics, cosmetics, and tobacco products. The FDA's authority derives primarily from the Federal Food, Drug, and Cosmetic Act (21 U.S.C. § 301 et seq.). The agency reviews and approves new drugs through a multi-phase clinical trial process that typically takes 10 to 15 years from initial discovery to market approval. The FDA's regulatory scope affects approximately 20 cents of every consumer dollar spent in the United States.

Centers for Disease Control and Prevention (CDC) — Also within HHS, the CDC serves as the nation's leading public health protection agency. It conducts epidemiological surveillance, investigates disease outbreaks, develops vaccination recommendations through the Advisory Committee on Immunization Practices (ACIP), and publishes the Morbidity and Mortality Weekly Report (MMWR). The CDC's quarantine authority under 42 U.S.C. § 264 allows it to take measures to prevent the introduction and spread of communicable diseases.

Centers for Medicare and Medicaid Services (CMS) — CMS administers Medicare (covering approximately 65 million beneficiaries), Medicaid (covering approximately 90 million beneficiaries), the Children's Health Insurance Program (CHIP), and the Health Insurance Marketplace established by the Affordable Care Act. CMS is the single largest payer in the U.S. healthcare system, with combined program spending exceeding $1.5 trillion annually.

Environmental and Energy Agencies

Environmental Protection Agency (EPA) — The EPA was established in 1970 by executive order and subsequent congressional action. It administers and enforces the major federal environmental statutes: the Clean Air Act (42 U.S.C. § 7401 et seq.), the Clean Water Act (33 U.S.C. § 1251 et seq.), the Resource Conservation and Recovery Act (governing solid and hazardous waste), the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, commonly known as Superfund), and the Toxic Substances Control Act. The EPA sets National Ambient Air Quality Standards (NAAQS), regulates water pollutant discharges through the National Pollutant Discharge Elimination System (NPDES), and manages the cleanup of contaminated sites nationwide.

Department of Energy (DOE) — The DOE manages the nation's nuclear weapons program through the National Nuclear Security Administration (NNSA), oversees national laboratories conducting fundamental and applied research, regulates civilian nuclear power plant safety (through the independent Nuclear Regulatory Commission), and administers energy efficiency standards for appliances and buildings. The DOE's national laboratory system — including Los Alamos, Lawrence Livermore, Oak Ridge, and Argonne — employs tens of thousands of scientists and engineers.

Financial and Economic Regulatory Agencies

Internal Revenue Service (IRS) — A bureau within the Department of the Treasury, the IRS administers the Internal Revenue Code and collects approximately $4.7 trillion in gross tax revenue annually. The IRS processes over 150 million individual income tax returns per year, administers refundable tax credits (including the Earned Income Tax Credit and Child Tax Credit), enforces tax compliance through audits and collection actions, and grants and monitors tax-exempt status for qualifying organizations under Section 501(c) of the Internal Revenue Code.

Federal Trade Commission (FTC) — An independent regulatory commission established in 1914, the FTC enforces federal antitrust and consumer protection laws. Under Section 5 of the FTC Act (15 U.S.C. § 45), the FTC has authority to prohibit "unfair or deceptive acts or practices" in commerce. The FTC reviews proposed mergers and acquisitions under the Hart-Scott-Rodino Act, investigates deceptive advertising, and has become increasingly active in data privacy and technology competition enforcement.

Securities and Exchange Commission (SEC) — Established by the Securities Exchange Act of 1934, the SEC regulates the securities industry, stock and options exchanges, and publicly traded companies. The SEC requires public companies to file periodic disclosure reports (10-K annual reports, 10-Q quarterly reports, 8-K current reports), enforces insider trading prohibitions, and oversees the registration of securities offerings.

Consumer Financial Protection Bureau (CFPB) — Created by the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010, the CFPB regulates consumer financial products and services including mortgages, credit cards, student loans, and payday lending. The CFPB writes rules implementing consumer financial protection statutes, supervises financial institutions, and takes enforcement actions against companies engaged in unfair, deceptive, or abusive practices.

Federal Reserve System — The central bank of the United States, established by the Federal Reserve Act of 1913. The Federal Reserve sets monetary policy through the Federal Open Market Committee (FOMC), supervises and regulates banks, maintains the stability of the financial system, and provides financial services to depository institutions and the federal government. The Fed's dual mandate from Congress is to promote maximum employment and stable prices.

Law Enforcement and Justice Agencies

Department of Justice (DOJ) — The DOJ is the federal government's principal law enforcement agency, headed by the Attorney General. It encompasses the Federal Bureau of Investigation (FBI), the Drug Enforcement Administration (DEA), the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), the U.S. Marshals Service, and the Bureau of Prisons. DOJ divisions include the Civil Rights Division, the Antitrust Division, the Criminal Division, and the Environment and Natural Resources Division. U.S. Attorneys in 94 judicial districts prosecute federal crimes and represent the government in civil litigation.

Department of Homeland Security (DHS) — Established by the Homeland Security Act of 2002, DHS consolidated 22 previously separate agencies into a unified department focused on domestic security. Its components include Customs and Border Protection (CBP), Immigration and Customs Enforcement (ICE), the Transportation Security Administration (TSA), the U.S. Coast Guard, the Secret Service, U.S. Citizenship and Immigration Services (USCIS), and the Federal Emergency Management Agency (FEMA). DHS is the third-largest cabinet department, with approximately 240,000 employees.

Federal Emergency Management Agency (FEMA) — A component of DHS, FEMA coordinates the federal response to disasters and emergencies. When the President issues a major disaster declaration under the Robert T. Stafford Disaster Relief and Emergency Assistance Act (42 U.S.C. § 5121 et seq.), FEMA administers individual and public assistance programs, coordinates with state and local emergency management agencies, and manages the National Flood Insurance Program (NFIP).

Agriculture and Food Supply Agencies

U.S. Department of Agriculture (USDA) — The USDA administers programs spanning agricultural production, food safety, nutrition assistance, rural development, and natural resource conservation. Its agencies include the Food Safety and Inspection Service (FSIS), which inspects meat, poultry, and processed egg products; the Food and Nutrition Service (FNS), which administers the Supplemental Nutrition Assistance Program (SNAP, serving approximately 42 million people), the National School Lunch Program, and the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC); and the Natural Resources Conservation Service (NRCS), which provides technical and financial assistance for farmland conservation.

Food Safety and Inspection Service (FSIS) — FSIS employs approximately 7,800 inspection program personnel stationed in over 6,000 meat, poultry, and egg product processing plants. Federal inspection is mandatory for all meat and poultry products sold in interstate commerce under the Federal Meat Inspection Act (21 U.S.C. § 601 et seq.) and the Poultry Products Inspection Act (21 U.S.C. § 451 et seq.).

Transportation and Infrastructure Agencies

Federal Aviation Administration (FAA) — An agency within the Department of Transportation, the FAA regulates civil aviation safety, manages the national airspace system, certifies aircraft and pilots, and operates air traffic control. The FAA oversees approximately 45,000 flights per day across U.S. airspace. Its regulatory authority extends from aircraft design and manufacturing standards to pilot training requirements and airport safety protocols.

Federal Highway Administration (FHWA) — Also within DOT, the FHWA administers federal highway programs and distributes federal funding to states for highway construction and maintenance. The National Highway System encompasses approximately 164,000 miles of roadway designated as being most important to the nation's economy, defense, and mobility.

National Transportation Safety Board (NTSB) — An independent agency that investigates every civil aviation accident in the United States and significant accidents in other modes of transportation including railroad, highway, marine, and pipeline. The NTSB issues safety recommendations — over 15,000 since its establishment in 1967 — but does not have regulatory or enforcement authority; implementation depends on action by regulatory agencies such as the FAA, the Federal Railroad Administration, or the Pipeline and Hazardous Materials Safety Administration.

Labor and Workplace Agencies

Department of Labor (DOL) — The DOL administers and enforces federal labor laws governing wages, hours, workplace safety, employment discrimination, unemployment insurance, and workers' compensation. Key agencies within DOL include the Occupational Safety and Health Administration (OSHA), the Wage and Hour Division, the Bureau of Labor Statistics (BLS), and the Employment and Training Administration.

Occupational Safety and Health Administration (OSHA) — Established by the Occupational Safety and Health Act of 1970, OSHA sets and enforces workplace safety and health standards. OSHA covers approximately 130 million workers at over 8 million worksites. The agency conducts workplace inspections, issues citations for violations, and proposes penalties. The maximum penalty for a willful violation exceeds $150,000 per violation as adjusted for inflation.

Equal Employment Opportunity Commission (EEOC) — An independent commission that enforces federal laws prohibiting employment discrimination based on race, color, religion, sex (including pregnancy, sexual orientation, and gender identity), national origin, age (40 and older), disability, and genetic information. The EEOC investigates discrimination charges, attempts conciliation, and may file suit in federal court. In fiscal year 2023, the EEOC received approximately 81,000 new charge filings.

How Citizens Interact with Federal Agencies

Citizens interact with federal agencies through several formal channels established by law:

• Rulemaking comments — When an agency proposes a new regulation, the notice-and-comment process under the APA allows any person to submit written comments through the Federal Register and regulations.gov. Agencies must consider and respond to significant comments in the final rule.
• Freedom of Information Act (FOIA) requests — Under 5 U.S.C. § 552, any person can request access to federal agency records. Agencies must respond within 20 business days, with nine enumerated exemptions covering classified information, trade secrets, law enforcement records, and other protected categories.
• Administrative appeals — Individuals who receive adverse decisions from agencies (such as denial of benefits, permit refusals, or enforcement actions) typically have a right to administrative appeal before seeking judicial review.
• Congressional casework — Members of Congress maintain constituent services offices that assist individuals in navigating federal agency processes. Casework is a standard function of congressional offices and is available to all constituents regardless of the issue's complexity.
• Inspector General complaints — Each major agency has an Office of Inspector General (OIG) that investigates fraud, waste, and abuse within the agency. Citizens can report concerns through OIG hotlines established under the Inspector General Act of 1978.

The practical knowledge of which agency handles which function — and how to engage with that agency's specific processes — is among the most directly useful elements of civic literacy. When a consumer product causes injury, the relevant agency is the Consumer Product Safety Commission. When a workplace is unsafe, it is OSHA. When a bank engages in predatory lending, it is the CFPB. Correctly identifying the responsible agency is the first step in any meaningful interaction with the federal government.