Research has shown that an idle summer is not just boring; it can cost a student as much as two to three months of educational progress. Summer is critical to each child's development, both mind and body. Any meaningful attempts to get at America's equity divide and the consequent gap in opportunities for kids must include summer education as a key part of the solution. For more than 10 years, the Partnership for Children and Youth (PCY) has been working to raise awareness about the value of afterschool and summer programs, known collectively as "expanded learning time" (ELT). Children spend much more time out of school than in it. PCY, along with key partners, created the Summer Matters campaign: a collaborative statewide effort in California to raise awareness about this challenge and to build capacity across the state to address it. This work is being accomplished with training, coaching, and facilitation to build the capacity of schools and their community partners and through communications and advocacy to partners in education, policy, philanthropy, and direct service. The campaign strategies and initiatives are discussed in this article.