Moving from Europe the CLIL approach has expanded its relevance in the teaching and learning of content and language to Latin America. Hence, the study of the CLIL related methods is paramount for schools implementing this approach. Thereby, it is paramount to present the design of a training program for in-service teachers of primary education that fosters collaborative teaching and the development of critical thinking. In this design, the 4 Cs framework serves as a base for the program design. Here, a thorough revision of CLIL, collaborative teaching, and critical thinking is described. Likewise, Co-teaching, Project-Based Learning, and Task-Based learning are theoretical reviewed. This training program is student-centered and it involves active learning, in which, participants learn about the CLIL methodological and conceptual aspects introduced in the literature review. The results of this design are eight sessions, each of them with specific objectives towards CLIL implementation, collaborative teaching encouragement, and critical thinking promotion. These sessions have the purpose to make learning visible and meaningful through diverse learning experiences and materials based on CLIL design.