INTRODUCTION:
Regionalization remains a persistent challenge within the Brazil’s Unified Health System (SUS), and the Integrated Regional Planning (IRP) has been established as a tripartite strategy to induce the organization of actions and services into regionalized healthcare networks. Analyzing the implementation of public policies is inherently complex, particularly when addressing planning from a regional perspective. The Strategor theoretical framework, inspired by the French HEC Paris School, adopts the tetrahedron concept, which considers decision-making, structure, identity, and strategy as interconnected determinants, in which changes in one dimension affect the others, forming a dynamic system. This study aims to describe the implementation process of IRP as a tool for integrating Health Care Networks in the state of Espírito Santo, Brazil.

METHODS:
The Strategor theoretical-methodological model was applied to analyze the IRP implementation process. The method involved examining the strategies adopted by technical staff and managers within a health region, identifying elements related to decision-making processes, institutional structural dynamics, and features of regional identity.

RESULTS:
Integrated Territorial Institutional Support was adopted as the central strategy, integrating regional institutional support initiatives and consolidating the Macrorregional Working Group as a management mechanism. This arrangement fostered a sense of belonging, strengthened intermunicipal ties, defined shared objectives, and enabled the development of collective outputs, reinforcing the region as a locus for implementing the prioritized healthcare network. Identified facilitating factors included strategic alliances, a robust normative framework, integrated governance, and the operationalization of IRP. Limitations comprised state-level tutelage over municipalities, low institutionalization of IRP, and limited strategic command. The group proposed actions aimed at reorganizing the healthcare network and promoting changes in healthcare delivery.

CONCLUSIONS:
Institutional Support reshaped work processes and expanded institutional democracy, exerting a positive impact on the implementation of health policies oriented toward population health needs and grounded in values of cooperation and solidarity.