The case was argued on December 1, 2014, and presented the question of whether, under a line of cases beginning with Paralyzed Veterans of Am. v. D.C. Arena L. P., 117 F.3d 579 (1979), an opinion letter issued by DOL interpreting its regulations relating to a provision of the FLSA was procedurally invalid because the interpretation conflicted with DOL's earlier interpretation of the same regulations, but was nevertheless adopted without notice and comment. Reversing the decision of the D.C. Circuit, the Supreme Court held that "[the] exemption of interpretive rules from the notice-and-comment process is categorical, and it is fatal to the rule announced in Paralyzed Veterans." In other words, "...[b]ecause an agency is not required to use notice-and-comment procedures to issue an initial interpretive rule, it is also not required to use those procedures when it amends or repeals that interpretive rule."

All nine Justices joined or concurred in the judgment of the Court. The opinion and three concurrences demonstrate the complexity of the issues before the Court and also raise interesting questions about the future of Auer deference.