INTRODUCTION. Assessing the participation experiences of young people with significant intellectual and developmental disabilities (SIDD) in recreational activities is imperative to ensure these activities provide youth with optimal opportunities to develop skills needed for adulthood. Currently, no instrument accessible to youth with SIDD is available to asses these experiences. The Participatory Experience Survey (PES) and the Setting Affordances Survey (SAS) were developed to meet this need. METHOD. The PES was developed with input from a panel of youth with SIDD while they were participating in a summer program. A draft was then presented to three groups of stakeholders: parents of youth with SIDD, service providers, and experts in intellectual disability and/or program planning. After making revisions based on stakeholder feedback, cognitive interviewing was conducted with eight youth ages 14 – 22 with SIDD. Next, to examine feasibility of the PES, the survey was given to 10 youth with SIDD. After finalizing a draft of the PES based on youth feedback, questions for the SAS were written to align with topics on the PES. Finally, a program evaluation was conducted that provided an additional feasibility evaluation of the PES and SAS. RESULTS. Of the 24 initial questions on the PES, stakeholder groups identified 15 questions needing revision and suggested 7 additional questions. Youth feedback during cognitive interviewing identified 13 questions needing revisions and 4 needing removal. Changes were made to address three issues: word choice, understanding of concept, and questions relating to others. Administering the PES directly following an activity was found to be feasible, however, the length was shortened from 31 to 15 questions to provide an appropriate administration time (<5 minutes). CONCLUSION. The PES and the SAS proved to be relevant, accessible and feasible ways to assess the individual experiences of youth with SIDD in recreational settings and the affordances, measured objectively, of those settings. Use of these two measures may help programs to include young people with SIDD during program evaluations, resulting in better-structured, more supportive programs.