Educator teams consisting of a general education teacher and a special education teacher were recruited to participate in a project where they used the Systematic Supports Planning Process (SSPP) to plan, implement, and monitor individualized supports for students with intellectual and developmental disabilities (IDD) attending general education classrooms. Educators completed a survey before and after the project where they assessed their confidence in applying UDL principles and provided examples of how they applied UDL principles in their classrooms. Although quantitative responses indicated that the confidence levels of general education teachers and special education teachers increased following participation in the project, qualitative findings were mixed regarding specific actions that demonstrated how UDL principles were applied. The implications for future research and professional development on UDL and arranging individualized supports in general education classrooms for students with IDD are discussed. [This paper will be published in "International Journal of Developmental Disabilities."]