Scholarly criticism of standing doctrine is hardly new, but a core problem with standing jurisprudence remains overlooked: How do parties challenging administrative decisions factually prove that they have standing on appeal when appellate courts normally do not conduct fact finding? This Article attempts to tackle that problem. It combines a four-pronged normative procedural justice model with an empirical study of appellate cases to conclude that (1) although this issue arises in a relatively narrow set of cases, the number of such cases is growing and (2) existing judicial solutions to the problem are deficient. Thus, after exploring several options — including the possibility of abandoning the current standing test — we suggest that appellate courts should, as the D.C. Circuit currently does, require all petitioners to address standing in their opening brief. In addition, courts should require petitioners who are not directly regulated by the agency action in question to submit additional evidence to support their standing claim. Here, courts must be careful to separate facts from law. But if these preliminary submissions show there is a factual dispute on any element of standing, the court should refer the dispute to a magistrate judge, who will hold a hearing on the disputed issues and provide a report and recommendation to the appellate tribunal.