Although educators overwhelmingly embrace the concept of Universal Design for Learning (UDL), the field continues to lack a shared understanding of what UDL looks like in everyday instruction in K-12 classrooms and what it means to implement UDL with fidelity. This resource seeks wisdom from UDL researchers, professional development providers, and implementers (educators) on the topics of UDL implementation fidelity and measurement, and explores a tool designed to measure UDL implementation fidelity in the context of everyday instruction in K-12 inclusive classrooms.