Federal agencies and how regulations are made
There are 438 federal agencies, commissions, and departments. They employ roughly 3 million civilians. They make rules that affect nearly every aspect of American economic and civic life, and most Americans know almost nothing about how they work.
What agencies are
Federal agencies are created by Congress through enabling legislation, which defines their mission and grants them specific authority to act. The Environmental Protection Agency was created by statute in 1970. The Food and Drug Administration traces its authority to the Pure Food and Drug Act of 1906. Agencies are part of the executive branch -- they answer ultimately to the President -- but they exercise powers that look, in practice, like a combination of all three branches. They write rules (legislative-style), enforce them (executive-style), and adjudicate violations (judicial-style). This concentration of function in a single body has been constitutionally contentious from the beginning.
The Administrative Procedure Act
The Administrative Procedure Act, passed in 1946, governs how federal agencies make rules. Its central requirement is notice-and-comment rulemaking. Before an agency can issue a binding regulation, it must publish a proposed rule in the Federal Register, accept written comments from the public -- any person or organization can submit comments -- and meaningfully respond to significant comments before the rule is finalized. This process gives affected industries, advocacy groups, and ordinary citizens a formal voice in regulation. It also takes time: a significant rule often takes two to five years from proposal to finalization.
Independent agencies vs. executive agencies
Not all agencies are structured the same way. Executive agencies -- the EPA, the Department of Defense, the Department of Justice -- are headed by officials the President appoints and can fire at will. Independent agencies -- the Federal Trade Commission, the Securities and Exchange Commission, the Federal Communications Commission, the Federal Reserve -- are governed by multi-member commissions with staggered terms. The commissioners can only be removed for cause, not simply because the President disagrees with their decisions. This structure is designed to insulate certain regulatory functions from direct political pressure. Whether that insulation is constitutionally permissible has been litigated extensively.
Judicial review and the end of Chevron deference
Courts have always been able to strike down agency rules that are "arbitrary and capricious" -- meaning the agency failed to give a reasoned explanation for its decision. Courts can also strike down rules that exceed the agency's statutory authority. For 40 years, however, courts applied a doctrine known as Chevron deference: when a statute was ambiguous, courts would defer to the agency's reasonable interpretation of what Congress meant. In 2024, the Supreme Court overturned Chevron in Loper Bright Enterprises v. Raimondo, holding that courts must independently determine what statutes mean rather than deferring to agency interpretations. This shifts power from agencies to courts and makes agency rules more vulnerable to legal challenge.
Why this matters
The vast majority of federal rules that affect daily life do not come from acts of Congress. They come from agencies. The specific content of food safety standards, the permissible level of pollutants in the air, the required safety features in a car, the conduct rules for financial advisers -- all of this is set by agencies operating under broad statutory authority Congress has granted. Congress sets the direction; agencies fill in the details. Understanding how that detail-filling works -- and how it can be challenged -- is essential to understanding how the federal government actually governs.