The need for students trained in science, technology, engineering, and mathematics (STEM) jobs is growing rapidly in the United States, yet students do not enroll in the necessary courses to prepare for STEM careers. In a randomized controlled trial, parents in the utility–value intervention group received materials detailing the importance of STEM for their adolescents in high school. The intervention increased mathematics and science ACT scores and course-taking in high school. This greater high-school STEM preparation was associated, 5 y later, with increased STEM career pursuit.