This phenomenological case study explores the perceptions of high school administrators who have implemented Schoolwide Positive Behavior Interventions and Supports (SWPBIS) at the universal tier with fidelity. For this study, perceptions refer to the views and experiences of administrators implementing SWPBIS on the success and growth they have seen in their schools. The researcher was interested in determining whether these perceptions are related to the experienced successes. The study's theoretical framework was derived from theories of motivation and reinforcement. SWPBIS is discussed in the study as a positive reinforcer to stimulate learners to show positive outcomes. It is also addressed as an activator of intrinsic motivation among the learners. To carry out the research, the researcher opted for a phenomenological case study approach where SWPBIS is the main phenomenon of the study. Using purposeful sampling, seven respondents were selected from school administrators and other staff in the McComb School District, McComb, Mississippi. The study's independent variables were perceptions of the success of SWPBIS and perceived behavioral modifications. The dependent variable for the study was the success of SWPBIS. Data for the study was collected using a structured interview and analyzed qualitatively using a thematic model. The findings were presented according to the research questions and the themes developed by the researcher. The study's findings should clearly show the stakeholders' experiences in the SWPBIS process and how these can be used to guide future implementation for better results.[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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]