On January 6, 2026, Noah Marks (UNC) presented Tax Regulations After Loper Bright: A Preliminary Analysis (with Conor Clarke (Wash. U.)) at the New Voices in Administrative Law Workshop at the Association of American Law Schools (AALS) Annual Meeting in New Orleans.

The abstract follows.

This article discusses the implications of Loper Bright Enterprises v. Raimondo for the judicial review of tax regulations. Before Loper Bright, the Supreme Court held in the 2011 Mayo Foundation case that Chevron governed such judicial review—and that there was no justification for a tax-specific deference regime. We consider the status of this doctrine now that Loper Bright has overruled Chevron. In particular, we consider whether a return to tax-specific, pre-Mayo Foundation caselaw is appropriate or desirable.

Part I situates Loper Bright in the historical trajectory of judicial review of tax regulations, tracing the doctrinal evolution from National Muffler, to Chevron, to Mayo Foundation. Part II considers which aspects of Mayo remain and whether National Muffler returns to legal relevance in the wake of Loper Bright. Part II also parses National Muffler to demonstrate that its test closely echoes, but is not identical to, Skidmore, which Loper Bright offered as an example of how judicial review of agency regulations should work. Finally, Part II highlights that National Muffler’s renewed relevance is not merely a matter of academic curiosity, given the Tax Court’s recent invocation of the test in Hamel v. Commissioner. 

Part III zooms out and considers the broader implications of a potential return to National Muffler. If National Muffler is indeed returning to prominence, that may suggest a return to a world of agency-specific doctrinal deference tests. In that connection, we also highlight a previously under-appreciated universe of pre-APA Supreme Court caselaw involving Treasury Regulations and highlight examples of cases that courts and litigants can draw on to shape and influence the judicial review of Treasury Regulations going forward.