With a national emphasis on integrated science, technology, engineering, and mathematics (STEM) education in K-16 courses, incorporating technology in a meaningful way is critical. This research examines whether STEM and non-STEM teachers were able to incorporate technology in STEM courses successfully with sufficient professional development. The teachers in this study consisted of faculty from middle schools, high schools, and colleges recruited for STEM Guitar Building institutes held between 2013 and 2016. Each teacher participated in a 50-hour professional development opportunity in the manufacture of a solid-body electric guitar and received instruction on how to teach integrated STEM Modular Learning Activities (MLAs), which are aligned with the Common Core mathematics standards and the "Next Generation Science Standards (NGSS)". The data collected include pre- and postassessment from 769 students in three grade bands (grades 6-8, 9-12, and undergraduate level from 15 states). The results showed statistically significant gains at the p < 0.05 level across all 12 of the core MLAs, with no statistically significant difference between STEM and non-STEM instructors for all except two MLAs. The two MLAs that did reveal a statistically significant difference were more technical--Set Up and Computer Aided Design/Computer Aided Manufacturing Systems (CAD/CAM). These results show non-STEM and STEM teachers alike in this study were able to successfully incorporate technology in "NGSS"-aligned integrated STEM lessons, as evidenced by student learning gains.