STEM education has become strategically important to increase college readiness of high school graduates in mathematics and science, cultivate STEM interest in students, boost STEM majoring students, and prepare students for 21st century workforce. The purpose of this study is to investigate a new STEM Project-based learning model developed by Harmony Public Schools (HPS). We used theoretical sampling and 11 students (5 seniors, 5 juniors, and 1 sophomore) were interviewed. Interview transcripts were analyzed by using grounded theory coding and constant comparative analysis. As a result of the analysis, a new STEM education model named the STEM Students on the Stage (S.O.S. TM) was emerged and defined. The emerging substantive theory suggests that through the STEM S.O.S. model, students increased their conceptual understanding, STEM interest, and research interest in higher education and developed self-confidence, and skills in technology, life and career, communication and collaboration and these skills continued to improve circularly. Findings were discussed in the context of STEM education and its effects on students’ interest in STEM careers.