Research and theory suggest that students learn more effectively when they perceive course content as relevant to their futures. The current research assessed the impact of CareerStart, a middle grades instructional strategy designed to advance the occupational relevance of what students are being taught in the core subjects—math, science, language arts, and social studies. CareerStart was introduced randomly in 7 of 14 middle schools in a diverse district with 3,295 students followed for 3 years. The analyses examined impact on end-of-grade test scores on math and reading exams. Findings confirm a significant treatment effect for math performance but no effect for reading performance.