This study examined the characteristics of 10 science, technology, engineering, and mathematics (STEM) focused high schools. A comparative case designed was used to identify key components of STEM school designs. Schools were selected from various regions across the United States. Data collected included websites, national statistics database, standardized test scores, interviews and published articles. Results from this study indicate that there is a variety of STEM high school programs designed to increase students' ability to pursue college degrees in STEM fields. The school mission statements influence the overall school design. Students at STEM schools must submit an application to be admitted to STEM high schools. Half of the STEM high schools used a lottery system to select students. STEM high schools have a higher population of black students and a lower population of white and Hispanic students than most schools in the United States. They serve about the same number of economically disadvantaged students. The academic programs at STEM high schools are more rigorous with electives focused on STEM content. In addition to coursework requirements, students must also complete internships and/or a capstone project. Teachers who teach in STEM schools are provided regularly scheduled professional development activities that focus on STEM content and pedagogy. Teachers provide leadership in the development and delivery of the professional development activities. [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.]