The purpose of this qualitative research was to understand how the COVID-19 pandemic shaped the lived experiences and stress of high school graduates who were enrolled in advanced academic courses during the 2020-2021 school year. This multiple case study explored how the COVID-19 pandemic affected the experiences of AP/IB high school graduates during their senior year and how this pandemic might have contributed to elevated levels of stress. It is vital for educators to better understand the factors that are detrimental to the health of their students. The following research questions guided this study: (a) How do AP/IB high school graduates in the Class of 2021 describe their lived experiences during senior year in the midst of COVID-19? (b) What contributed to their stress while completing their advanced coursework? (c) What helped to mitigate their stress while completing their advanced coursework? Consistent with previous findings in the literature, the findings of this qualitative multiple case study indicated that learning from home presented its fair share of challenges, the circumstances of the pandemic left participants isolated at home with fewer opportunities to socialize with peers, the college application process was a major stressor for many participants, and there were apparent gender differences in how the participants described their senior year. This research was necessary and significant as it provided deeper insight as to how the COVID-19 pandemic shaped the experiences of recent high school graduates and helped answer why high school students are stressed to the point of negative health outcomes. [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.]