Today, the U.S. Supreme Court released a highly anticipated decision addressing the question of whether to overrule Auer v. Robbins, which generally requires courts to defer to agencies’ reasonable interpretations of their own ambiguous regulations. In a splintered 5-4 decision, the Court declined to abolish Auer deference (sometimes referred to as Seminole Rock deference) as a matter of stare decisis, but reiterated and expanded important limitations on the doctrine’s application. Significantly, under Kisor, courts should apply Auer deference only if they determine that (i) a regulation is genuinely ambiguous after exhausting all traditional tools of interpretation, (ii) the agency’s interpretation is reasonable, and (iii) the “character and context of the agency interpretation entitles it to controlling weight,” because it reflects the official, expert, considered, and consistent judgment of the agency.