Forty Years of Deference to Federal Agencies Ended in a Single Supreme Court Opinion
For forty years, when a federal agency interpreted an ambiguous statute in a way that was merely reasonable, even if a court might have read the law differently, courts were required to defer to the agency’s interpretation. This principle, known as Chevron deference, shaped how the EPA, the FDA, the Army Corps of Engineers, the FCC, and virtually every other federal regulatory agency operated, and how courts reviewed challenges to their decisions.
On June 28, 2024, the Supreme Court eliminated that framework. In Loper Bright Enterprises v. Raimondo, decided almost exactly forty years after the original Chevron ruling, the Court held in a 6-3 decision that Chevron deference is inconsistent with the Administrative Procedure Act and that courts, not agencies, must exercise independent judgment in determining what a statute means.
This article explains what the Chevron doctrine actually was, where it came from, what the Supreme Court decided in Loper Bright, and what the end of Chevron deference means in practice for anyone dealing with a federal regulatory agency.
What the Chevron Doctrine Was
The Chevron doctrine took its name from the 1984 case Chevron U.S.A., Inc. v. Natural Resources Defense Council, Inc.. The case arose from a dispute over the Clean Air Act Amendments of 1977, which required states that had not met national air quality standards to establish permit programs regulating “new or modified major stationary sources” of air pollution.
The Environmental Protection Agency interpreted “stationary source” to allow a “bubble policy,” under which an entire industrial plant containing multiple pollution-emitting devices could be treated as a single source. Under this approach, a plant could modify or add equipment without a new permit as long as the plant’s total emissions did not increase. The Natural Resources Defense Council challenged this interpretation, arguing that each individual pollution-emitting device within a plant should be treated as its own “source,” which would have required permits far more often.
The Clean Air Act did not define “stationary source” in a way that resolved this dispute, and the Court found that Congress had not directly addressed the precise question at issue. Faced with this ambiguity, the Supreme Court held that the EPA’s interpretation was a permissible reading of the statute and upheld it. The majority opinion, written by Justice Stevens, was joined by five other justices; Justices Marshall, Rehnquist, and O’Connor took no part in the consideration or decision of the case.
In doing so, the Court articulated what became known as the two-step Chevron framework. First, a court asks whether Congress has directly spoken to the precise question at issue. If congressional intent is clear, that intent controls, and the inquiry ends there. Second, if the statute is silent or ambiguous on the specific issue, the court asks whether the agency’s interpretation is based on a permissible construction of the statute. If it is, the court defers to the agency, even if the court might have reached a different interpretation on its own.
For four decades, this framework governed how courts reviewed an enormous range of agency action, environmental regulations, health and safety rules, financial regulations, immigration policy, and far more. Chevron deference meant that when a statute was ambiguous, the tie effectively went to the agency, not to whichever party was challenging the agency’s interpretation.
What the Supreme Court Decided in Loper Bright
Loper Bright Enterprises v. Raimondo arose from a very different regulatory context: commercial herring fishing. The Magnuson-Stevens Act authorized the National Marine Fisheries Service to require vessels to carry federal observers, but a group of fishing companies argued the statute did not authorize the agency to require the vessels themselves to pay for those observers’ costs. Lower courts, applying Chevron, deferred to the agency’s interpretation that it could require this. The fishing companies asked the Supreme Court to reconsider Chevron itself.
The Supreme Court heard Loper Bright alongside a companion case, Relentless, Inc. v. Department of Commerce, raising the same underlying question from a different federal circuit. On June 28, 2024, the Court issued its decision, overruling Chevron in a 6-3 opinion written by Chief Justice Roberts. Justice Jackson did not participate in Loper Bright itself, having recused due to her prior involvement in the case while serving on the D.C. Circuit, but joined the dissent in the companion Relentless case along with Justices Kagan and Sotomayor.
The majority’s central reasoning rested on the Administrative Procedure Act of 1946, the foundational statute governing how federal agencies operate and how courts review their actions. The Court held that the APA requires courts to decide all relevant questions of law and to interpret statutory provisions, and that this requirement is inconsistent with a framework that requires courts to defer to an agency’s interpretation simply because a statute is ambiguous. As the majority put it, courts may not defer to an agency interpretation of the law simply because a statute is ambiguous, because agencies have no special competence in resolving statutory ambiguities. Resolving ambiguities is, the Court held, a job for courts.
Under the Loper Bright framework, courts must now exercise independent judgment in determining the meaning of a statutory provision, including those that involve a technical or scientific matter within an agency’s area of expertise. Courts may still consult an agency’s interpretation as part of that independent analysis, particularly where an interpretation has been consistent over time or reflects considered judgment, a form of respect sometimes called Skidmore deference, but an agency’s interpretation is no longer entitled to controlling weight merely because the statute is ambiguous and the interpretation is reasonable. How exactly Skidmore deference applies in the wake of Loper Bright remains an unsettled question. Federal circuit courts have applied it inconsistently since the decision, with some courts leaning on it heavily when evaluating agency interpretations and others questioning what role, if any, it continues to play.
Importantly, the Court was explicit that Loper Bright does not automatically invalidate regulations that were previously upheld under Chevron. The Court stated that prior cases that relied on the Chevron framework are still subject to statutory stare decisis, meaning that a specific holding that a particular agency action was lawful under Chevron does not automatically become unlawful simply because the Chevron framework itself has been overruled. What changes going forward is how courts evaluate new or ongoing challenges to agency interpretations.
Why the Court Overturned a Forty-Year-Old Precedent
The majority’s opinion framed Loper Bright not as a novel assertion of judicial power, but as a return to what the Constitution and the APA always required. Chief Justice Roberts wrote that the judiciary has the responsibility to decide whether the law means what the agency says, invoking the same foundational principle articulated by Chief Justice Marshall in Marbury v. Madison: that it is the province and duty of the judicial department to say what the law is.
The dissent, authored by Justice Kagan and joined by Justices Sotomayor and Jackson, argued that Chevron deference reflected a sensible allocation of institutional responsibility. Agencies, the dissent argued, often have far more subject-matter expertise than generalist judges when it comes to technical regulatory questions, whether a particular chemical compound falls within a statutory category, how a financial instrument should be classified, or what emissions standard a piece of industrial equipment should meet. The dissent warned that eliminating Chevron would shift enormous interpretive authority to courts on exactly the kinds of technical questions courts are least equipped to resolve, and would inject new instability into decades of settled regulatory practice.
This disagreement reflects a broader and longstanding debate in American law about the proper balance between the expertise of administrative agencies and the constitutional role of courts in interpreting the law, a debate that Loper Bright has now resolved, at least for now, decisively in favor of the courts.
What Has Changed in Practice Since Loper Bright
In the time since Loper Bright was decided, its practical effects have begun to take shape, though commentators broadly agree that the full picture will take years to develop.
The first major Supreme Court application of Loper Bright came on March 4, 2025, in City and County of San Francisco v. Environmental Protection Agency, a case involving Clean Water Act permitting for the city’s combined sewer system. The Court’s opinion expressly invoked Loper Bright, declining to accept EPA guidance that the Court found was not codified in the statute the agency was interpreting, and emphasizing that courts are not obligated to accept administrative guidance that conflicts with the statutory language it purports to implement.
A second significant application followed on May 29, 2025, in Seven County Infrastructure Coalition v. Eagle County, Colorado, a case concerning the scope of environmental review required under the National Environmental Policy Act for a proposed railway project. The decision reaffirmed the Court’s approach to judicial review of agency environmental determinations in the post-Loper Bright landscape, an application directly relevant to the kinds of federal environmental review questions that intersect with land use and development.
More broadly, Loper Bright has been credited with an increase in litigation challenging federal agency interpretations. A 2025 survey of in-house counsel and litigation leaders found that a substantial majority anticipated greater regulatory uncertainty following the decision, and that the average number of regulatory proceedings per company increased from the prior year. Commentators have also noted that Loper Bright, combined with the same term’s decision in Corner Post, Inc. v. Board of Governors of the Federal Reserve System, which addressed how the statute of limitations applies to challenges against agency rules, has opened the door to challenges against agency interpretations that previously would have been considered too late or too well-settled to revisit.
At the same time, early appellate decisions applying Loper Bright have shown some restraint. Federal courts of appeals reviewing agency decisions in specialized areas, such as patent and trade matters before the Patent and Trademark Office and the International Trade Commission, have in some cases concluded that Loper Bright changes less than initially feared where an agency’s authority rests on an express statutory delegation rather than on filling a statutory gap through interpretation. The practical scope of Loper Bright‘s effect appears, a year and a half after the decision, to depend heavily on the specific statute and agency action at issue.
Why This Matters Beyond Federal Regulatory Law
Loper Bright is, on its face, a case about federal administrative law, the relationship between federal courts and federal agencies like the EPA, the FDA, and the FCC. But the underlying question it addresses, who gets to say what a law means when its text does not provide a clear answer, is the same question that runs through constitutional litigation generally.
The Environmental Law practice at Kassouni Law regularly involves situations where a federal agency’s interpretation of its own statutory authority affects private property, whether through wetlands determinations under the Clean Water Act, endangered species designations, or other federal environmental regulatory actions that can significantly restrict what a property owner may do with their land. Under the Chevron framework, a property owner challenging such a determination faced an additional, often decisive obstacle: even if a court might have read the underlying statute differently, the agency’s interpretation would typically prevail as long as it was reasonable. Loper Bright removes that obstacle. A property owner challenging a federal agency’s interpretation of its statutory authority can now ask a court to determine, using its own independent judgment, what the statute actually means, without the agency’s thumb on the scale.
This connects to a theme that runs through the firm’s broader constitutional practice: the principle, traceable to Marbury v. Madison and reaffirmed in Loper Bright, that courts, not the other branches of government, bear ultimate responsibility for determining what the law requires. Whether the question involves the constitutionality of a state agency’s permit conditions or the statutory authority underlying a federal regulation, the Constitutional Law practice at Kassouni Law addresses the common thread: that government action, at every level, is subject to judicial determination of whether it is lawful.
Frequently Asked Questions
What was the Chevron doctrine and why was it called that?
The Chevron doctrine, also called Chevron deference, was a legal framework established by the Supreme Court’s 1984 decision in Chevron U.S.A., Inc. v. Natural Resources Defense Council, Inc.. It required federal courts to defer to a federal agency’s reasonable interpretation of an ambiguous statute that the agency administers, even if the court might have interpreted the statute differently on its own. The framework took its name from the case in which it was established, which involved a challenge to the EPA’s interpretation of the term “stationary source” under the Clean Air Act.
When was Chevron deference overturned, and by what case?
Chevron deference was overturned on June 28, 2024, by the Supreme Court’s decision in Loper Bright Enterprises v. Raimondo, decided in a 6-3 opinion written by Chief Justice Roberts. The decision was issued almost exactly forty years after the original Chevron decision in 1984. The Court held that Chevron deference is inconsistent with the Administrative Procedure Act, which requires courts to exercise independent judgment in interpreting statutes rather than deferring to an agency’s interpretation simply because a statute is ambiguous.
Does overturning Chevron mean existing federal regulations are now invalid?
No. The Loper Bright decision does not automatically invalidate regulations or agency actions that were previously upheld under the Chevron framework. The Court specifically noted that prior decisions relying on Chevron remain subject to ordinary principles of stare decisis. What changes is how courts evaluate new or ongoing challenges to agency interpretations going forward: courts now exercise independent judgment rather than deferring to an agency’s reasonable interpretation of an ambiguous statute.
What replaces Chevron deference now that it has been overturned?
Under Loper Bright, courts exercise independent judgment to determine the best reading of a statute, using traditional tools of statutory interpretation. Courts may still consider an agency’s interpretation as part of that analysis, particularly where the interpretation reflects long-standing or carefully considered agency views, a more limited form of consideration sometimes referred to as Skidmore deference, but the agency’s interpretation is no longer entitled to controlling weight simply because the statute is ambiguous and the agency’s reading is reasonable. Where Congress has expressly delegated authority to an agency to fill a specific statutory gap, for example through formal rulemaking on a defined question, that express delegation continues to carry legal weight.
How does the end of Chevron deference affect challenges to agency actions involving private property?
Federal agencies such as the EPA and the Army Corps of Engineers regularly make determinations, such as wetlands designations under the Clean Water Act or species habitat determinations, that can significantly affect what a private property owner may do with their land. Before Loper Bright, a property owner challenging such a determination on the grounds that the agency had misread its statutory authority faced an additional hurdle: courts were required to defer to the agency’s interpretation as long as it was reasonable, even if the court might have read the statute differently. After Loper Bright, a court reviewing such a challenge exercises independent judgment in determining what the statute actually authorizes, without that additional layer of deference to the agency’s own interpretation of its authority. Kassouni Law addresses these kinds of federal regulatory questions as part of its environmental law and constitutional property rights practice.
This article is for informational purposes only and does not constitute legal advice. No attorney-client relationship is created by reading this content. Contact Kassouni Law for a consultation regarding your specific situation.
