A lively debate has emerged over the deferential standard of review courts apply when reviewing an agency’s interpretation of its own regulations. That standard, traditionally associated with Bowles v. Seminole Rock & Sand Co. and now more frequently attributed to Auer v. Robbins, states that a court must accept an agency’s interpretation of its own regulations unless the interpretation is plainly erroneous or inconsistent with the regulation. This Article argues that a court’s choice of method for interpreting regulations — including how it determines which agency interpretations are inconsistent with the regulation — may be just as important, if not more important, to the outcome of review as the standard of review the court applies. The point that the outcome of review is a function not only of the standard but also of the interpretive method is long-acknowledged in the debate over Chevron. It applies to review of the interpretation of regulations as well. If the ultimate framework of review is a problem with two important dimensions — the standard of review and the interpretive method — then there is reason to evaluate the likely effects of different methods of regulatory interpretation. The Article then argues that a purposivist approach, one which requires readings of regulations to be consistent with those in the regulation’s preamble, identifies a narrower range of acceptable readings and offers greater notice of the regulation’s meaning than relying on the regulation’s text alone. As a result, this regulatory purposivist method holds promise for addressing many of the concerns motivating challenges to the Seminole Rock/Auer standard whether or not that standard is retained
