[This paper is part of the Focused Collection on Curriculum Development: Theory into Design.] When disseminating curricula, typically only the physical curriculum materials are transferred from the instructor to another. However, left as artifacts in the curricula are a set of epistemological beliefs held by the creators and designers of the materials. These epistemological beliefs are often underpinning the activity structures and strongly influence how the curriculum materials are implemented in the classroom, particularly when those beliefs differ from those activated by the instructor. In this paper, we articulate three epistemological beliefs that are built into the University Modeling Instruction curriculum that are essential for running the large-group discussions, which are a crucial part of the curriculum. We highlight how these beliefs are built into the student-facing and instructor-facing curricular materials and the influence of these beliefs in the interpretation and implementation of the curriculum materials. Finally, we discuss the implications on curriculum dissemination, on the adoption and adaptation of curriculum materials, and training models for instructors beyond the curriculum designers.