Across the US, government officials, social entrepreneurs, nonprofit leaders, philanthropists, and impact investors talk about the need to pursue not just program outputs but “positive outcomes”—results that make a genuine difference in beneficiaries’ lives. For more and more social change efforts, the key to success lies in clearly defining the desired results for beneficiaries. This article argues that the willingness of more and more stakeholders to ask questions about outcomes, and then to combine that process with data-driven decision making will bring positive outcomes for those who are most in need.