The Supreme Court’s recent decision in Agostini v. Felton is its most important case involving Catholic schools since the landmark 1971 ruling in Lemon v. Kurtzman. In Agostini, a closely divided Court took the unusual step of overturning its 1985 decision in Aguilar v. Felton, which prohibited the on-site delivery of Title I services to students enrolled in religiously affiliated nonpublic schools. In light of the potential ramifications of Agostini, this article reviews the Court’s rationale in detail before reflecting on how Agostini might affect the delivery of educational services under Title I and the Individuals with Disabilities Educational Act to students in Catholic schools.