A fundamental challenge in the process of regional planning and management in Iran is the failure to achieve the goals set out in approved development documents. This stems from a structural disconnect between the functional-spatial environment and the institutional-administrative system. This research aims to conduct an in-depth analysis of how political, administrative, and institutional fragmentation has hindered the realization of the objectives outlined in the Tehran Urban Region development document. Furthermore, it proposes an integrated Multi-Level Governance (MLG) framework based on a "spatial-institutional alignment model." Employing a descriptive-analytical methodology, the study utilizes documentary research, qualitative content analysis of territorial development documents, and structural modeling. The findings indicate that the primary factors contributing to the failure of the plan include: the structural disconnect between the functional urban region and the rigid boundaries of administrative-territorial divisions; horizontal fragmentation driven by destructive competition among peripheral municipalities; vertical fragmentation resulting from the sectoral, siloed approach of national institutions; and a lack of coordination in the management of urban fringes. This diagnostic analysis underscores the necessity of transitioning from traditional management to an integrated Multi-Level Governance (MLG) model—encompassing structural, procedural, relational (actor-based), and financial dimensions. The operationalization of this approach is envisioned through three key mechanisms: a joint Tehran-Alborz Coordination Council, an integrated spatial observatory, and a fund dedicated to regional development and the sharing of benefits.