Keywords: Cross-sectoral partnerships, foundation strategy, government-philanthropic relations, public-private partnershipsIntroductionWhile philanthropy and government have a history of joining forces to address issues that range from education and public health to economic development, such efforts have often been informal and episodic with a good dose of happenstance. In recent years, there is growing evidence that foundations of various types and scale are taking steps to engage with government on a more formalized and continuous basis and contemplating new models of how they can partner to achieve greater impact (GrantCraft, 2010). At the same time, government at the local, state, and national levels is beginning to view public-private partnerships as a strategy for more effective public-problem solving. In effect, both sectors are becoming more intentional about their desire to collaborate across sectors to address a wide array of public problems.A number of forces are compelling these new approaches. Government at all levels is fiscally constrained, severely limiting the ability to mount new programs and even sustain existing ones. Thus, while governments have vast resources relative to foundations, they understand that partnerships with foundations may give them added flexibility to pursue new initiatives or find innovative solutions to critical public problems (Goldsmith & Eggers, 2004; Salamon, 2002; Goldsmith, Georges, & Burke, 2010). At the same time, the growth of foundation assets has slowed in recent years, leading philanthropists to look to new strategies to achieve greater impact in pursuit of their missions, including partnerships with government.The idea of working across sectors is increasingly prevalent at the state and local levels, where there is a greater familiarity between policymakers and foundation leaders and where a larger number of foundations have a greater sense that their resources can make an impact.1 But it has also taken hold at the federal level with a number of initiatives, including the Social Innovation Fund, Investing in Innovation, and Promise and Choice Neighborhoods programs, that have sought to leverage the sustained involvement of philanthropy in public-problem solving (Abramson, Soskis, & Toepler, 2012a, 2012b).Yet, the desire on the part of foundations to partner with government and government to partner with philanthropy is not enough. The costs of partnering - even within the same sector - are high. Identifying issues of common interest and bringing parties together in the hopes of developing a partnership entails costs and carries risks. The conflicting rationales and institutional logics that guide the behavior of philanthropy on the one hand and government on the other make collaboration across the sectors even more difficult. Due to these challenges, many potential partnerships are not even contemplated or those that are tried fail to get off the ground. Even in cases where partnerships across sectors develop, more often than not partners are working together for the first time. These partnerships tend to be ad hoc, time-limited, and episodic, making their potential to achieve impact more tenuous. This translates into fewer partnerships across the sectors than might otherwise be possible.One potential solution to address the challenges of philanthropy and government working together is a new institutional innovation - the office of strategic partnerships (OSP).2 These offices are designed to catalyze and foster partnerships between government and philanthropy (and sometimes business) by bridging differences between sectors. They are emerging at the local, state, and federal levels of government and focus on stimulating and accelerating partnerships between sectors. While they are formally referred to by different names and have different origins, rationales, and organizational structures, they represent an effort to create an infrastructure to help the sectors work together better by lowering the transaction costs of partnering. …