This casebook emphasizes current doctrine and its historical evolution in exploring the four basic foundations of federal administrative law: separation of powers, statutorily and constitutionally required procedures for agency adjudication and rulemaking, scope of judicial review of agency action, and the availability and timing of judicial review. The book concentrates on federal rather than state administrative law, on the belief that an understanding of federal law can be translated into other settings if so desired. This edition of the book maintains the straightforward organization and don't-hide-the-ball presentation that has characterized the book since its inception. The Ninth Edition contains four new principal cases and numerous new notes and note cases, including a new framework for the materials on separation of powers. The book prominently continues, from the prior edition, to expand materials on statutory interpretation to accommodate the increasing inclusion of Administrative Law in the first-year curriculum.