The University of Washington's (UW) "Access to Informal STEM Learning (AccessISL)" project employs a student-centered approach and potentially transformative practices that embrace the social model of disability, social justice education, disability as a diversity issue, intersectionality, and universal design. A leadership team of interns--each member a UW student with a disability or a museology graduate student--along with project staff engage with the UW Museology program to identify and implement strategies for making ISL activities and courses more welcoming and accessible to individuals with disabilities. Initial outcomes of "AccessISL" intern engagement include specific changes within ISL programs, increased awareness and implementation of universal design principles in the Museology graduate program, and expanded skills about the accessible/universal design of informal learning within future professionals who served as interns in "AccessISL."