A federal statute that requires the administrative agencies to satisfy procedural requirements (referred to as notice-and-comment rulemaking) in developing and issuing regulations (5 U.S.C. § 553). Under the APA, an administrative agency must (subject to limited exceptions):

After considering relevant matter presented, an agency must include in its regulations a concise general statement of the regulations' basis and purpose.

Notice-and-comment rulemaking under the APA is intended to:

If an agency fails to follow the APA in rulemaking, the resulting regulations can be subject to legal challenge in the courts (see Legal Update, Two District Courts Block Trump Administration's Final ACA Contraceptives Rules). For example, in a decision involving the Affordable Care Act's (ACA's) contraceptives mandate, the US Court of Appeals for the Third Circuit held that Pennsylvania and New Jersey (as plaintiffs) were likely to succeed in proving that several federal administrative agencies violated the APA by issuing interim final regulations (IFRs) without first engaging in notice-and-comment rulemaking (Pennsylvania v. United States, 930 F.3d 543 (3d Cir. 2019); see Legal Update, Third Circuit Upholds Nationwide Injunction Blocking Trump Administration's ACA Contraceptives Final Rules). The Third Circuit also concluded that the agencies could not cure this defect by engaging in notice-and-comment rulemaking in finalizing the regulations (that is, after it issued the IFRs).