The United States has a vast and complex system of law enforcement, extending far beyond local police departments. At the national level, federal law enforcement agencies play a critical role in protecting the country’s borders, enforcing specialized laws, investigating major crimes and upholding national security. These agencies operate under the jurisdiction of the federal government and often have authority that spans across state lines.
From the Federal Bureau of Investigation (FBI) to the U.S. Secret Service, these institutions carry out missions that require advanced training, broad legal authority and specialized expertise. If you’ve ever wondered how many agencies there are, what they do or how to join their ranks, this guide will walk you through everything you need to know about federal law enforcement in the United States.
How many federal law enforcement agencies are there?
The United States is home to dozens of federal law enforcement agencies, each empowered with a unique jurisdiction and mission.
While more than 100 agencies possess some form of law enforcement authority, roughly 65 of these have sworn officers authorized to carry firearms and make arrests. These agencies operate under departments like Justice, Homeland Security, Interior and others, addressing a vast range of federal priorities from counterterrorism to environmental protection.
List of 15 major U.S. federal law enforcement agencies
The following are some of the largest and most prominent federal law enforcement agencies in the United States. Each employs sworn federal officers — individuals authorized to carry firearms, make arrests and enforce federal laws nationwide. These agencies fall under departments such as Justice, Homeland Security, Treasury and the Interior, and represent the core of federal law enforcement in the U.S.
This curated list includes:
- Agency name
- Estimated number of sworn officers
- Brief description of the agency’s mission
- Link to the official website
- Link to the agency’s career/hiring page
Note: This is not a complete list of every federal agency with law enforcement powers. Agencies like the Smithsonian Police, Pentagon Force Protection Agency, NOAA Office of Law Enforcement and others also perform specialized enforcement duties. For a full directory, consult the USA.gov A-Z Index or Wikipedia’s list of U.S. federal law enforcement agencies.
| Agency | Sworn Officers (approx.) | Mission | Website | Careers |
|---|---|---|---|---|
| Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) | 2,600 | Regulates firearms, explosives, arson, and trafficking crimes. | atf.gov | ATF Careers |
| Bureau of Indian Affairs (BIA) | 300 | Provides law enforcement on tribal lands. | bia.gov | BIA Jobs |
| U.S. Customs and Border Protection (CBP) | 45,000 | Protects borders and enforces immigration and customs laws. | cbp.gov | CBP Careers |
| Drug Enforcement Administration (DEA) | 4,600 | Investigates drug trafficking and enforces narcotics laws. | dea.gov | DEA Careers |
| Diplomatic Security Service (DSS) | 2,000 | Protects U.S. diplomats and investigates document fraud. | state.gov | DSS Careers |
| Environmental Protection Agency – Criminal Investigation Division (EPA CID) | 200 | Investigates environmental law violations. | epa.gov | EPA Careers |
| Federal Bureau of Investigation (FBI) | 13,000 | Handles terrorism, counterintelligence, and major federal crimes. | fbi.gov | FBI Careers |
| Federal Protective Service (FPS) | 1,000 | Secures federal buildings and facilities. | FPS Site | FPS Careers |
| Immigration and Customs Enforcement – Homeland Security Investigations (ICE-HSI) | 6,800 | Investigates immigration violations and transnational crime. | ice.gov | ICE Careers |
| Internal Revenue Service – Criminal Investigation (IRS-CI) | 2,200 | Investigates tax fraud and financial crimes. | irs.gov | IRS-CI Careers |
| National Park Service – Law Enforcement Rangers (NPS) | 1,400 | Enforces law in national parks and public lands. | nps.gov | NPS Careers |
| United States Secret Service (USSS) | 3,200 | Protects national leaders and investigates financial and cyber crimes. | secretservice.gov | Join USSS |
| U.S. Capitol Police (USCP) | 2,000 | Protects Congress and the U.S. Capitol complex. | uscp.gov | USCP Careers |
| U.S. Marshals Service (USMS) | 3,500 | Handles fugitive operations, witness protection, and court security. | usmarshals.gov | USMS Careers |
| U.S. Postal Inspection Service (USPIS) | 1,300 | Investigates mail fraud, identity theft, and postal crimes. | uspis.gov | USPIS Careers |
How do I become a federal law enforcement officer?
For those looking to pursue a career in federal law enforcement, the path is challenging, competitive and rewarding. While each agency sets its own criteria, there are several common threads: most positions require U.S. citizenship, a bachelor’s degree, a clean background, and the ability to pass a series of written, physical and psychological evaluations. Many roles also require candidates to be under a certain age at the time of appointment — typically under 37 years old, though waivers may be granted in some cases.
Training is intensive. Officers attend programs at institutions like the Federal Law Enforcement Training Centers (FLETC) or the FBI Academy, where they receive instruction in firearms, law, investigative techniques, defensive tactics and agency-specific operations.
Though the process varies by agency, here’s how it looks at a few of the largest federal employers:
FBI Special Agent Jobs
To become a Special Agent with the Federal Bureau of Investigation (FBI), applicants must be between 23 and 36 years old, hold a bachelor’s degree and have at least two years of full-time professional experience. The hiring process includes multiple written assessments, a structured interview, a physical fitness test and a full background investigation. Recruits complete approximately 20 weeks of training at the FBI Academy in Quantico, Virginia.
Customs and Border Protection (CBP) Officer Requirements
Entry-level CBP Officers must pass a written entrance exam, structured interview, medical screening, polygraph and a background check. Qualified applicants attend 19 weeks of training at FLETC. The age limit is generally under 40. CBP assignments may include land borders, airports or ports of entry.
Secret Service Uniformed Division Careers
Applicants to the U.S. Secret Service Uniformed Division follow a rigorous process that includes a written exam, panel interview, polygraph, medical and psychological evaluations, and a background check. Training starts at FLETC, followed by advanced instruction in Washington, D.C., focusing on protection operations, emergency response and threat assessment.
Each agency publishes its hiring criteria and current openings on its official career portal. Before applying, prospective officers should explore the mission of the agency, its core responsibilities and the working environments typical of its assignments.
Conclusion
Federal law enforcement agencies play a vital role in upholding national laws, protecting public safety, and enforcing regulations across borders, ecosystems, cyberspace, and beyond. Whether you’re driven by justice, service, or a passion for specialized investigations, the world of federal law enforcement offers diverse, impactful career paths.
Explore each agency’s mission and hiring process to find where you can serve — and protect — at the highest level.
Police1 is using generative AI to create some content that is edited and fact-checked by our editors.
