Given concerns that students are not prepared for STEM (science, technology, engineering and mathematics) college and careers, some states have created schools to enhance STEM proficiency. Inclusive STEM schools are designed to develop STEM interest and talent in groups of students underrepresented in STEM careers. We examined inclusive STEM schools to see whether those students were better prepared for postsecondary work than their matched peers in traditional schools. Then, we determined whether STEM schools provided a greater benefit to students underrepresented in STEM: girls, members of underrepresented minority groups, and economically disadvantaged students. Students in STEM high schools were more likely to pass advanced math and science classes, earn potential college credits, and graduate than those in traditional high schools. The effect of attending a STEM school was stronger for girls, economically disadvantaged, and underrepresented minority group students.