This guide states the law governing federal agency rulemaking, adjudication, and judicial review. Part 1 covers the Administrative Procedure Act's architecture and the definitions that decide most threshold disputes. Parts 2 and 3 cover notice-and-comment rulemaking, its content requirements, the logical outgrowth and statement-of-basis obligations, the exemptions including good cause, and the distinction among legislative rules, interpretive rules, and guidance documents. Part 4 covers the analytical overlays — centralized regulatory review, the Regulatory Flexibility Act, the Paperwork Reduction Act, and the Congressional Review Act. Parts 5 and 6 cover formal and informal adjudication, licensing protections, and the reviewability, standing, ripeness, finality, exhaustion, and timing questions that decide whether a challenge is heard. Parts 7 and 8 cover the standards of review under section 706, the end of Chevron deference after Loper Bright, the narrowed Auer doctrine, the major questions doctrine, the administrative record, and the available remedies. Later parts address agency delay, petitions for rulemaking, and state and local administrative practice.