Grade placement of newcomer immigrants into U.S. High schools continues to challenge many educators. This becomes even more significant when newcomer immigrants come from countries where education systems are different; or in some cases, their educational development is completely disrupted. Also, curriculum analyses have suggested math concepts become more complex and conceptually difficult from one grade level to another. While the traditional age-based placement provides a one-size-fits-all approach for everyone, the implication of this approach is important to understand. Hence, this work examines, explores, and supports the understanding of the impact of newcomer immigrant students' age-based placement on the current school system, students' academic outcomes, and their overall well-being in U.S. high schools. The researcher employed a phenomenological qualitative study to analyze data collected from high school math teachers and school administrators through surveys. Among the primary findings highlighted were, language barriers, educational disparities, and insufficient math knowledge as significant hurdles in instructing newcomer students. In conclusion, implementing placement criteria that are more flexible by considering students' academic backgrounds and English language proficiency levels rather than solely relying on age. [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/en-US/products/dissertations/individuals.shtml.]