The doctrine of exhaustion of administrative remedies says that a person challenging an agency decision must first pursue the agency’s available remedies before seeking judicial review. It was created by courts in order to promote an efficient justice system and autonomous administrative state. Congress has since written exhaustion requirements into many statutes to ensure and guide its application. Consequently, a court interpreting one of these statutory versions must first decide whether it is a jurisdictional rule or not. The fallout from this decision is the topic of this Note. By definition, jurisdictional rules are rigid: Courts may not create exceptions to them, parties may not waive or forfeit them, and they will loom over the proceedings from start to finish. Faced with a jurisdictional exhaustion requirement, courts have had to choose between diluting the concept of jurisdiction and allowing injustice. In this Note, I look for a way out of this tradeoff. I argue that statutory exhaustion requirements are neither jurisdictional nor non-jurisdictional rules, but rather mandatory rules with a particular set of effects on courts and parties. Courts, for example, may not apply equitable exceptions to statutory exhaustion requirements, but agencies may waive or forfeit them. I define this “mandatory” exhaustion by looking to case law, jurisdiction theory, constitutional structure, and the purposes of exhaustion. I also develop an exception for constitutional claims that arise outside of an agency’s proceedings. This exception helps avoid the threat to separation of powers that requiring exhaustion for such claims would create. As a result, if courts used mandatory exhaustion then they would be empowered to avoid injustice without creating a conceptual mess. Commentators have suggested that exhaustion requirements might be mandatory in nature, and the Second Circuit has treated them as such. But neither has provided much guidance on what that means. I try to fill in that gap by developing a descriptive and normative case for categorizing them as mandatory rules.