Student self-confidence is important to any attempt to increase interest and achievement in Science, Technology, Engineering, and Math (STEM) education. This study presents a longitudinal examination of Fab Lab Tulsa's impact on attitude and self-efficacy toward STEM education among middle-school aged students. Paired samples t-test showed a statistically significant increase in self-efficacy among students attending four or more STEM sessions. Moreover, self-efficacy had a significant positive association with both the impact and skill level toward STEM as reported by participating students. Similarly, student attitudes toward STEM showed a significant positive association with both impact and skill level. Results of this study suggest a positive impact of Fab Lab Tulsa educational programs on STEM among students.