The need to create accessible digital materials became evident when the COVID-19 pandemic shifted nearly all learning online in 2020 and early 2021. Inspired to create professional development that was sensitive to our campus needs at a challenging time, the campus Workgroup on Accessibility Practices created an intervention in the form of a 10-day accessibility challenge. To keep participants (N = 198) motivated and engaged, the 10-Day Accessibility Challenge was designed with self-determination in mind. In this work, we describe the practice and use a mixed methods approach to evaluate its effectiveness. We find that shifting the campus culture toward accessibility and inclusion is an on-going process. To do so requires that campuses commit both time and tangible resources to increasing knowledge and implementation of accessibility principles. Challenge-type interventions can reach diverse constituencies, build greater familiarity and utilization of existing resources, and increase participant confidence around their ability to contribute to a culture of accessibility and inclusion.