The Administrative Procedure Act (APA) is a federal law prescribing the rules on the way in which administrative agencies of the federal government of the United States may propose and establish regulations.
According to the Federal Administrative Procedure Act, rulemaking is as “an agency process for formulating, amending, or repealing a rule.” The Act defines a rule as the “whole or a part of an agency statement of general or particular applicability and future effect designed to implement, interpret, or prescribe law or policy or describing the organization, procedure, or practice requirements of an agency.”
In Hercules, Inc. v. EPA, 598 F.2d 91, 117 (D.C. Cir. 1978), “Rule making” is defined as “agency process for formulating, amending, or repealing a rule. As per 5 USCS § 551, the primary purpose of APA is to regulate processes of rulemaking and adjudication.