The Tax Times: Post‑Loper Bright Tax And Other Agency Rules & Regulations Are Still Largely Being Upheld by the Courts

Tuesday, January 27, 2026

Post‑Loper Bright Tax And Other Agency Rules & Regulations Are Still Largely Being Upheld by the Courts

According to Law360, Appellate courts have mostly upheld federal agencies' interpretation of ambiguous statutes, including tax disputes, even after the U.S. Supreme Court's 2024 landmark decision that limited agency deference, a U.S. Department of Justice attorney said Thursday.

So far, the federal government has won 74 cases that challenged an agency's actions, which is roughly a 60% win rate, Lindsay Clayton, assistant director in the tax branch of the DOJ's Civil Division, said at the D.C. Bar's annual tax conference, held in Washington, D.C., and online.

The DOJ attorney previewed early findings from her analysis of circuit-level cases decided after the Supreme Court came out with its June 2024 opinion in Loper Bright Enterprises v. Raimondo. She said a more detailed report will be published in a few months in the DOJ Journal of Federal Law and Practice.

The early findings suggest that fears of a sweeping rollback of the regulatory state after justices issued the opinion in the Loper Bright case have not materialized, according to Clayton.

The government's 74 wins are comparable to the 81 cases in which courts upheld agency actions before the Loper Bright opinion, she said, citing the Cato Institute's analysis from the libertarian think tank's amicus brief filed while the case was pending. Clayton cautioned that there are still too few cases to really draw a major conclusion.

In the Loper Bright opinion, the Supreme Court majority overturned its own 1984 decision, known as the Chevron doctrine, which compelled courts in litigation to defer to an agency's interpretation of an unclear statute that Congress delegated to the agency to implement.

The outcome prompted to using other judicial review principles used in litigation, including the Skidmore deference, which the Supreme Court established in 1944. Skidmore is a less binding principle than the Chevron doctrine, which gave agencies automatic deference.

Speaking on the same panel as Clayton, Lisandra Ortiz of Miller & Chevalier Chtd. said there has not been many recent tax cases that apply factors that meet the Skidmore deference.

"We have a small pool of decided tax cases" that deal with validating agency regulations, Ortiz said. Within that, she said, "there are even fewer cases that actually have any substantive analysis of Skidmore."

Ortiz listed 2025 decisions that upheld or partly upheld agency actions in FedEx Corp. v. U.S. in a Tennessee federal court, 3M Co. v. Commissioner in the Eighth Circuit and Lissack v. Commissioner in the D.C. Circuit.

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