The Supreme Court’s recent decision in Azar v Allina Health Services, Inc opened and then declined to resolve a new question of administrative law. In that case, the Court affirmed the DC Circuit’s holding that the Medicare Act, unlike the Administrative Procedure Act (APA), did not exempt so-called “interpretive rules” from notice and comment. Crucially, however, the Supreme Court declined to give any further guidance as to what rules the Medicare Act’s notice-and-comment provision does cover. This lack of guidance added further confusion to an already-murky area of law: the DC Circuit’s current interpretation of the Medicare statute, which is the only one presently left standing, has no fixed limits and is tethered only to a dictionary definition. This Comment argues that courts should clarify the reach of the Medicare Act’s notice-and-comment provision by looking to existing case law interpreting the APA’s exemption to notice and comment for procedural rules. This reading would provide the administrators of the Medicare system with much-needed guidance as to which rules they must subject to notice and comment. With the effective administration of over sixty million Americans’ health insurance on the line, clarifying the statute’s notice-and-comment requirement is a necessary “procedure.”