To improve access to primary care in underserved areas, policies have promoted multidisciplinary medical homes (e.g., family health groups, patient-centered medical homes). Through the development of medical homes, the expected improvements in accessibility concern both the likelihood of accessing primary care and the frequency of healthcare utilization. This study analyzes the impact of collaborative organizational models within territorial medical home networks, on various performance dimensions and using a simulation-based approach. The goal is to develop a decision-aid tool to assist local managers in optimizing organizational design. We assess different collaboration scenarios, including intra-home teamwork among healthcare professionals and inter-home cooperation. Our findings highlight that simply establishing medical homes is not enough—effective collaboration frameworks are essential to maximizing efficiency and improving primary care accessibility.