Federal agencies apply hundreds of statutes every day and must decide what they mean. When a court reviews an agency's action, whose reading of the statute counts? The Court has answered in different ways over eighty years. You saw the setting in holding the bureaucracy accountable. Like the substantive canons, deference rules tell a court which way to lean when a statute is unclear.
Key idea
Under Skidmore (1944), an agency's reading gets weight according to its power to persuade: the thoroughness of its reasoning, its consistency and its expertise. Under Chevron (1984), courts deferred to an agency's reasonable reading of an ambiguous statute it administered. Mead (2001) limited Chevron to agency readings carrying the force of law. The Court overruled Chevron in 2024; courts now decide for themselves what a statute means, giving agency views the weight their reasoning earns, as under Skidmore.
| Skidmore (1944) | Chevron (1984) | |
|---|---|---|
| Clear statute | the court applies it | the court applies it (step one) |
| Ambiguous statute | the court decides, weighing the agency's view | the court accepts any reasonable agency reading (step two) |
| Agency's view | weight depends on care, consistency and expertise | controlling if reasonable |
| Why | agencies have experience and information courts lack | Congress was presumed to leave gaps for agencies to fill |
Why it works
Chevron rested on a presumption that when Congress left a gap or ambiguity in a statute an agency administers, it meant the agency, which has expertise and answers to an elected President, to fill it. Skidmore rested on a different idea: an agency's reading is evidence of the best meaning, and it persuades to the degree its reasoning is careful and consistent. In United States v. Mead Corp. (2001) the Court said Chevron applied only when Congress had given the agency power to make rules carrying the force of law and the agency used it, as in notice-and-comment rulemaking; other agency readings, such as tariff rulings, got Skidmore weight. Judges and scholars long debated Chevron. Supporters said it respected expertise and political accountability; critics said it let agencies, rather than courts, say what the law is.
Worked example: Chevron's two steps
In 1995, an agency reads an unclear statutory term broadly. A court thinks the narrower reading is somewhat better, but the agency's is reasonable. What did the court do under Chevron?
- Step one: is the statute clear? No, it is ambiguous on this point.
- Step two: is the agency's reading reasonable? Yes.
- So the court defers, even though it would have chosen the narrower reading on its own.
Answer: It upheld the agency's reading.
Worked example: Skidmore weight
An agency issues an informal guidance letter reading a statute. The letter is short, gives no reasons and contradicts the agency's own earlier letters. How much weight would it get under Skidmore?
- Skidmore weighs thoroughness, the validity of the reasoning and consistency with earlier and later statements.
- No reasons and inconsistency weigh against it.
Answer: Little weight.
Common mistake
Mixing up Skidmore and Chevron. Under Skidmore the agency's reading persuades only as much as its reasoning earns; under Chevron a reasonable reading controlled. Another slip: describing Chevron as current law. The Court overruled it in 2024.
This is an educational course, not legal advice.