Over the years, cultural and linguistic diversity in schools across Europe has significantly increased due to migration and refugee flows. In response, international organizations, such as the Council of Europe and the European Commission, advocate intercultural education as both an educational strategy and a social policy tool to foster inclusion, address inequality, and build cohesive societies. This study contributes to the intercultural education literature by addressing an underexplored area: the process of translating intercultural policies into school practices. Using Street-Level Bureaucracy theory and qualitative research in Trento, Italy, it highlights the mechanisms and challenges shaping teachers’ practices and the extent of the policy–practice gap. Furthermore, the research also contributes to the Street-Level Bureaucracy theory. It shows that teachers can act as innovators in the policy implementation process. By engaging civil society members, notably students and members of migrant communities, as co-implementers, teachers reshape policy ecosystems through participatory and bottom-up approaches.