There is growing interest on the part of government, philanthropy and business to work together to achieve greater impact. Partnerships that span the sectors have the potential to achieve more than any sector can achieve on its own by leveraging the strengths of each. However, such partnerships also give rise to added costs and entail greater risks. To address these challenges, offices of strategic partnerships are emerging at the federal level to provide an infrastructure to catalyze cross-sectoral partnerships. This report examines 21 such offices in federal departments and agencies whose purpose is to facilitate and accelerate partnerships with philanthropy and business -- ranging from the Department of Housing and Urban Development and the Department of Education, to the Department of State and the Agency for International Development, to the Department of Homeland Security and the Federal Emergency Management Agency. The formation of these offices has been driven by champions within government -- many with prior experience in philanthropy or business -- that have witnessed the power of working collaboratively with other sectors. Their actions have often been reinforced by executive orders and other directives conducive to their growth. In the case of those offices that have been created in the last few years, they have also been encouraged by the examples of their more established counterparts.