Abstract: In the Bankruptcy Abuse Prevention and Consumer Protection Act of 2005 (BAPCPA), Congress included a provision requiring bankruptcy courts evaluating individual debtors' financial circumstances to utilize certain monthly expense standards developed by the Internal Revenue Service for assessing taxpayers' ability to pay their taxes (the Standards). While the IRS retains a great deal of discretion in applying the Standards for its own purposes, bankruptcy courts have interpreted the BAPCPA as giving the Standards binding force in the bankruptcy context. This unusual arrangement - where a statute regulating one substantive area incorporates documents promulgated by an unrelated administrative agency for use in a different substantive area - presents bankruptcy judges with a set of unfamiliar and difficult administrative law questions. To what extent, if at all, should bankruptcy courts defer to IRS statements, contained in documents other than the Standards themselves, about how the Standards should be applied? May the IRS alter the Standards for its own purposes but not for bankruptcy purposes, or vice versa? What procedures must the IRS use when it modifies the Standards, especially in light of the fact that the Standards now have an apparently binding effect in bankruptcy cases? These questions have become even more pressing since the IRS in 2007 amended the Standards without public notice and comment and provided different effective dates for IRS and bankruptcy court use of the amended Standards. This essay explains from the standpoint of administrative law the difficulties that these questions present and suggest a few possible (and in some cases competing) administrative law theories for thinking about them.