Teacher shortages in STEM (Science, Technology, Engineering, and Mathematics) fields have long been a concern, yet contemporary challenges present a unique predicament. Despite historical recruitment successes, the persistence of this issue has led to temporary solutions that often fall short of addressing the root causes. Consequently, school districts resort to hiring individuals lacking proper certification or expertise, or relying on substitutes, to fill crucial STEM teaching positions. Student academic achievements can be impacted as effective STEM instruction demands not only a deep understanding of the subject matter content but also robust pedagogical practices. To shed light on the complexities surrounding teacher attrition in STEM education, this study employs a multiple-case study approach. Through coding semi-structured interviews, the experiences and perspectives of former STEM educators are examined, providing insights into the factors influencing their departure. By delineating these factors at the individual, local, and state levels, this research contributes to a nuanced understanding of STEM teacher attrition and offers implications for policy and practice. [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.]