The newest science standards and national economy demand a committed emphasis to STEM integration in K-12 education. The need for STEM programs in K-12 education continues to grow, specifically in the formative adolescent years. In response, one public school district pursued and was awarded a grant to implement a STEM program. This research study is an investigation into the impact of this program on both students and teachers throughout the school district. The purpose of this mixed method, three-article dissertation was to probe the effectiveness of the district-wide STEM program on adolescents and their teachers. The researcher was particularly attentive to the relationship between teacher efficacy in STEM and students' confidence in and attitudes toward STEM, whether a difference existed in groups of teachers and students who were surveyed before and after the STEM program was implemented, and whether a difference existed in terms of race and gender regarding students' levels of STEM confidence. Historical data including both teacher and student responses that were collected by the district were used for a variety of analyses. The studies found that there was no relationship between teachers' STEM efficacy and students' STEM confidence, but there was an increase in both groups' levels of STEM efficacy and confidence after the program. Analysis of teachers' comments indicated that three areas of priority concentration for STEM professional development are time, efficacy, and equipment. The studies also found that there were no differences regarding gender or race in terms of STEM confidence among students. Females' STEM confidence increased after the STEM program, while minority students' STEM confidence did not. The studies provide both quantitative and qualitative analyses to the national focus on STEM education and best practices for equipping teachers and their students to have positive experiences with STEM learning. [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.]