This study reports on the implementation of mother tongue education in linguistically diverse contexts (LDC), or locations where a number of mother tongues (MT) are spoken. In 2012, the Government of the Philippines implemented a Mother Tongue-based Multilingual Education program for the first 4 years of schooling (K-3). The Philippine Department of Education proposed two program models to assist schools to cater for linguistic diversity: a 'multiple monolingual' model, which groups students with the same MT in separate monolingual classes, and a 'lingua franca' model, which adopts a widely used language as medium of instruction in all classes. Three years into the program, a nationwide survey including 50 schools in LDC was conducted to identify challenges that teachers faced and strategies in program implementation. Responses to the survey described modifications of the Department-proposed models, illustrating how educators embraced the multi-layered character of linguistic diversity through context-driven program strategies. Results also identified program areas for which schools need additional support, such as the organization and teaching of classes in which a range of MTs is spoken. The adopted strategies demonstrate a localized realization of a national policy and provide policy-makers and implementers with a range of classroom realities and possible options for improving educational outcomes for students in complex and dynamic multilingual settings.