Under the ESA, areas that otherwise qualify as critical habitat “may” be excluded from a designation if the government determines that the benefits of exclusion would outweigh the benefits of inclusion, and if the exclusion would not result in the species’ extinction. Federal courts have uniformly held that a decision not to exclude an area is immune from judicial review under the APA, pointing to that Act’s bar on judicial review of agency action “committed to agency discretion by law.” But contrary to the case law, application of this bar should not depend on whether Congress has enacted permissive statutory language; instead, it ought to depend on the nature of the administrative action itself. If an agency action falls within a category traditionally held to be immune from judicial review—for example, official immunity or political question—then the bar should apply. Applying this understanding to the ESA, decisions whether to exclude an area from critical habitat should be reviewable, at least for conformity with the Constitution and basic principles of rational agency decisionmaking.