The prevalence of stunting in Aceh Province has experienced a gradual decline (averaging 3.42% per year) despite the introduction of various programs and substantial budget allocations. This study aims to develop a Collaborative Governance Plus policy model through the integration of local wisdom to strengthen polycentric collaboration between the regional government, the Aceh Customary Council (MAA), and the Ulema Consultative Council (MPU). A qualitative study employing a multi-case approach was conducted in Sabang City, Nagan Raya Regency, and Gayo Lues Regency three regions with distinct characteristics and varying rates of stunting reduction. Data were collected through in-depth interviews with 18 key informants, policy document review, and observation, then analyzed thematically. The findings reveal that the integration of local wisdom remains partial and has not been systematically institutionalized. The roles of MAA and MPU within the policy cycle are highly limited and tend to be more symbolic than substantive. The study produces a Collaborative Governance Plus model that positions the government, MAA, and MPU as equal centers of authority in stunting governance. This model offers mechanisms for institutionalizing collaboration, inclusive budgeting, and culturally-based indicators to generate policies that are not only technically effective but also possess cultural legitimacy and social sustainability.