The problem addressed in this case study was to understand the criteria elementary school principals used to select students as participants in their STEM programs. Therefore, this case study aimed to explore and understand the criteria or protocol that elementary principals use to include low-income Black and Hispanic students in STEM programs within a Central Florida District. The research questions centered on how principals used STEM criteria for student inclusion and the elementary school principal's role with low-income Black and Hispanic students in the STEM curriculum in a Central Florida District. Additionally, a case study design that best aligned with the study's goals provided participants with a platform to share their thoughts regarding the topic. Purposive sampling was completed of 126 Central Florida school sites for this case study with those participants who were in a position to provide information best aligned with the focus of the study. Data were collected and triangulated through individual structured interviews with elementary school principals, field notes from site observations of the STEM programs, and demographic data (ethnicity and low-income status). The data were manually transcribed and coded. The emergent findings included the following: (a) principals used varying criteria for their STEM programs based on the needs of their students, and (b) participants suggested that understanding STEM and its benefits to students through professional development supports the implementation of STEM. Building on the findings from this study, the practical applications include establishing STEM Cohorts to support leader efficacy, professional learning for school leaders, and leveraging STEM resources. However, more research is needed to examine the criteria for STEM access for students using quantitative methods and how elementary principals' experiences impact their ethics and values as decision-makers and educational leaders. [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.]