The purpose of this phenomenological study was to explore the perceptions of high school seniors diagnosed with mental or physical impairments regarding the effectiveness of their 504 academic accommodations. The approach of this qualitative study was transcendental phenomenology. Phenomenology is defined as the qualitative approach to research that encompasses the exploration of lived experiences of the participants. The participants for this research study were high school graduates who had 504 accommodations during high school. Participants for this study contributed by answering open-ended questions from an interview guide. In the course of the in-depth data analysis, the interviews were coded, and common themes were extracted. The analyzed data resulted in three themes: teacher/administration support, students overwhelmed by diagnosis, and grit. The results of the study may be useful to administrators, teachers, and parents regarding the effectiveness of 504 accommodations in the high school setting and using this information may allow schools to improve accommodations for students with mental and physical limitations to serve students more effectively. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]