KMAN Publication Incorporation Interdisciplinary Studies in Society, Law, and Politics 3060-5687 In Press 2027 01 01 Criteria for Distinguishing the Supplementation and Modification of Law in Government Rulemaking within the Iranian Legal System (The Scope of Government Rulemaking from the Perspective of Modifying and Supplementing the Law) Criteria for Distinguishing the Supplementation and Modification of Law in Government Rulemaking within the Iranian Legal System (The Scope of Government Rulemaking from the Perspective of Modifying and Supplementing the Law) 1 23 EN Journal Article 2026 04 08 <p>Government rulemaking in the Iranian legal system, particularly through regulations, cabinet resolutions, and administrative circulars, constitutes an essential instrument for the implementation of statutes and the fulfillment of the government’s administrative functions. Nevertheless, a persistent question concerns the boundary between government rulemaking undertaken for the purpose of implementing the law and rulemaking that, in practice, results in altering the substance or legal effects of the law. The principal issue addressed in this study is the criteria by which, within the framework of Iranian public law, a distinction can be drawn between the “supplementation of law” and the “modification of law” in government rulemaking. Using a descriptive-analytical method and relying on library-based sources, constitutional principles—particularly Article 138 of the Constitution—and the rules governing the hierarchy of legal norms, this study examines the issue. The principal finding is that the decisive criterion for distinguishing between these two forms of rulemaking is not the formal designation of the regulation but rather its substantive and legal effect on the statutory provision. Accordingly, where a regulation merely establishes executive, administrative, and technical arrangements for implementing the law, resolves practical ambiguities, or determines mechanisms for giving effect to a statutory provision, it falls within the scope of supplementing the law. By contrast, where a regulation expands or restricts the scope of application of the law, alters the conditions for the application of a statutory provision, or modifies statutory rights, obligations, exceptions, or legal effects, it exceeds the limits of the government’s executive authority and amounts to modification of the law. It is therefore concluded that the government’s rulemaking authority must be understood as subordinate to and serving the implementation of legislation, rather than operating independently of the law or in conflict with the legislative intent.</p> https://www.journalisslp.com/index.php/isslp/article/download/592/1182