Public participation in administrative rulemaking is typically embodied in notice-and-comment procedures essentially mandating the publication of a proposed rule and an opportunity for the public to submit comments thereon prior to its adoption. This article presents a comparative analysis of the notice-and-comment regimes under the Philippine Administrative Code (PAC) and the United States’ Administrative Procedure Act (APA). In stark contrast to the Philippine legal framework which renders compliance with the notice-and-comment procedure practically discretionary on the part of the agency, the APA prescribes the conduct of notice-and-comment as a general rule, and courts rigorously police agencies’ compliance with the procedure. This article argues that the mandatory (or discretionary) nature of the notice-and-comment mechanism impinges on the efficacy of procedural challenges to administrative rules, the standard of judicial review applied to agency statutory interpretation, and the statutory creation of public norms. The article hopes to inspire a re-evaluation of the Philippine framework while providing valuable lessons to other jurisdictions with similar legal architectures.