The principle of civilian supremacy is a constitutional foundation of Indonesia’s state system, affirming that the highest authority in governance belongs to civilian institutions rather than the military. This study examines the constitutionality of restrictions on civil positions for active Indonesian National Armed Forces (TNI) members as an instrument for strengthening civilian supremacy, and analyzes the appointment of active TNI members to civil positions against this principle. This research employs a doctrinal legal approach, utilizing statutory, theoretical, historical, and comparative methods, with the Philippines as a comparative country. The findings reveal that Article 47 of Law No. 3 of 2025 on TNI has not fully functioned as a consistent instrument for strengthening civilian supremacy, as it still includes four agencies—Bakamla, BNPB, BNPP, and BNN—that lack substantive connection to national defense functions. The appointment of three active TNI officers based on Decree No. Kep/1545/XII/2024 to agencies outside the limitatively enumerated list, without prior resignation or retirement from active military service, violates Article 47(2) of the TNI Law and reflects a substantive blurring of the boundary between defense and civil governance functions, resembling the dual-function (dwifungsi) practice of the ABRI era. These findings indicate that without normative correction, the consolidation of civilian supremacy built since the 1998 reform is at risk of regression. The study recommends that the Parliament harmonize Article 47 by limiting the list exclusively to agencies with substantive defense functions, that the Constitutional Court provide authoritative interpretation in the ongoing material review, and that the TNI Commander establish administrative verification procedures prior to issuing appointment decrees for active soldiers to civil positions.