Collective impact is an increasingly popular approach to addressing persistent social problems. It takes a place-based systems approach to social change and compared with other forms of collaboration is meant to be more structured and strategic. Such an approach is intuitively appealing, and it has the support of stakeholders at the local level, the state level, and even the White House. However, engaging in strategic, cross-sector collaboration is challenging. This brief draws on the experiences of five committed collective impact communities participating in the Ford Foundation's Corridors to College Success initiative to expose some of the practical challenges of translating the theory of collective impact into action.