The Supreme Court’s most recent foray into clarifying when courts ought to “defer” to agency interpretations of their own regulations—Kisor v. Wilkie— resulted in little clarity. Instead, in the words of Justice Gorsuch’s concurrence, the Court left in place a “zombified” doctrine that kept alive the applicable form of deference—known as “Auer deference”—while appearing to narrow the scope of the doctrine’s application and to reduce the weight given to agency constructions. 

In the wake of Kisor, precisely what is the path forward for agency interpretations of statutes? In a concurring opinion in Kisor, Chief Justice Roberts said that, in his view, “[i]ssues surrounding judicial deference to agency interpretations of their own regulations are distinct from those raised in connection with judicial deference to agency interpretations of statutes enacted by Congress.” He explained that he did “not regard the Court’s decision today to touch upon the latter question.”

The modern case that is associated with that question—Chevron U.S.A. Inc. v. Natural Resource Defense Council, Inc.—held (much like Auer) that ambiguities in statutes that an agency administers are effectively delegations of authority to fill the statutory gap in a reasonable manner. According to Chevron, filling in those gaps—even when doing so requires interpretation— involves a difficult policy choice that agencies, rather than courts, should make. Chevron thus conceived of a two-step process—the first step of which asks whether the statute’s plain terms “directly address[] the precise question at issue” and the second step of which asks whether, if the statute is ambiguous, the agency’s construction is “a reasonable policy choice for the agency to make.” Chevron has subsequently been cited in a vast number of the Court’s opinions, with the addition of many permutations and qualifications to this seemingly straightforward two-step process.

Aditya Bamzai, Judicial Deference and Doctrinal Clarity, 82 Ohio State Law Journal, 585–610 (2021).