Broadening participation in PreK-12 Science, Technology, Engineering, and Mathematics (STEM) provides ALL students with STEM learning experiences that can prepare them for civic life and the workforce. In this way, broadening participation has the potential to transform society by reducing social and economic inequities, and by bringing new knowledge to scientific problems and solutions. Schools, districts, and states must take deliberate action to broaden participation and create inclusive learning environments. These actions will vary at each level of the education system. This brief highlights steps for education decision-makers to take to improve STEM education for ALL students.