How the Two-Step Chevron Framework Dictated Federal Agency Power

Federal agencies no longer hold the automatic benefit of the doubt when interpreting ambiguous laws in court. The elimination of the two-step Chevron framework in June 2024 stripped executive departments of a powerful legal shield, exposing thousands of existing environmental, financial, and workplace regulations to renewed judicial scrutiny.

Before its reversal, the doctrine originated from a 1984 Supreme Court decision involving the Environmental Protection Agency's definition of a "stationary source" of air pollution under the Clean Air Act. The Court ruled unanimously that "if Congress has explicitly left a gap for the agency to fill, there is an express delegation of authority to the agency to elucidate a specific provision of the statute by regulation."[1]

To apply this principle, the Supreme Court established a rigid two-step test that federal courts were required to follow whenever a regulated entity challenged an agency's statutory interpretation. This test became the most cited framework in American administrative law, appearing in over 15,000 federal court opinions before its eventual demise.[4][5]

Step One asked a threshold question: Has Congress spoken directly to the precise question at issue? If the statute was clear and unambiguous, the court's inquiry ended there. The judiciary was obligated to enforce the plain meaning of the law, regardless of what the agency or the executive branch preferred.[1][4]

Determining ambiguity, however, proved highly subjective. Judges utilized traditional tools of statutory construction—examining text, structure, and legislative history—to ascertain congressional intent. According to analysis from the Fordham Law Review, approximately 39% of Chevron challenges were resolved at this initial stage, with courts frequently finding that Congress had indeed been clear.[3]

If the court determined the statute was silent or ambiguous, the framework forced the judge to proceed to Step Two. At this stage, the court could not impose its own preferred interpretation of the law. Instead, it had to ask only whether the agency's interpretation was based on a "permissible" or "reasonable" construction of the statute.[1][5]

Step Two was the engine of executive power. As long as the agency's reading was logical and not explicitly forbidden by the text, the court was required to uphold it. Research published in the Vanderbilt Law Review demonstrated that when cases reached Step Two, federal agencies won approximately 73% of the time, creating a formidable shield for executive action.[2]

The rationale behind this deference was twofold: expertise and political accountability. The 1984 Court reasoned that agencies possess technical expertise that generalist judges lack. Furthermore, agency heads are appointed by the President, making them indirectly accountable to the electorate, whereas federal judges are unelected and appointed for life.[1][4]

Over the decades, the framework expanded to cover nearly every facet of the administrative state. The Congressional Research Service noted that the doctrine applied equally to formal rulemakings, adjudications, and other agency actions carrying the force of law, centralizing immense interpretive authority within the executive branch.[5]

However, the doctrine's rigid application generated intense friction. Critics argued that the two-step test violated the Administrative Procedure Act of 1946 and Article III of the Constitution by forcing judges to abandon their core duty to say what the law is. This tension culminated in June 2024, when the Supreme Court formally struck down the 40-year precedent, returning statutory interpretation entirely to the judiciary.

Without the automatic deference of Step Two, federal agencies must now convince courts that their interpretation of an ambiguous statute is the best reading, not merely a reasonable one. The burden of proof has shifted back to the government, fundamentally altering how future regulations will be drafted and defended.[6]