Keywords: Collaborative leadership, cross-sector collaboratives, networks, effective grantmakingWhy leadership? Leaders create forward movement through executing strategies for organizational and community change that results in sustained and positive outcomes. Collaborative leadership is especially important in cross-sector collaboratives; it is a specific type of leadership that promotes strategic relationship building, resource-sharing, honest and open dialogue, and a deeper understanding of the important social issues that collaboratives work to address. These skills are crucial when striving for significant results for communities that require collaborative efforts across agencies and sectors. Leadership can and must be developed to promote a focus on results, to create effective strategies to address major social challenges, and to align resources and actions that lead to the execution of strategies at a scope and scale high enough to make a difference.As cross-sector collaboratives become the rule rather than the exception in addressing social change, growing attention has been paid to the specific components that lead to collaborative success (e.g., Bryson, Crosby & Stone, 2006; Thomson & Perry, 2006). We build on recent discussions of collective impact' (Kania & Kramer, 2011) and argue that grantmakers can support self-sustaining and independent cross-sector collaboratives by building the leadership capacity of those individuals participating in collaboratives. A successful and pragmatic method to leadership development is to build the capacity of collaborative leaders while focusing them on their work. In this model of development, collaborative members are supported by neutral, but skillful, facilitators who work to develop participants' collaborative leadership skills and promote both public accountability for the group and individual accountability within the group. We also argue that although a skillful facilitator is critical, through strong collaborative leadership skills and improved accountability, it is the collaborative itself, rather than the facilitator, that influences positive community change. Using data collected from past participants of the Annie E. Casey Foundation's Leadership in Action Program (LAP), we test a model of collaborative success put forth in the Theory of Aligned Contributions (TOAC) (Pillsbury, 2008).This research makes significant contributions to the literature, as researchers have yet to demonstrate the direct impact of collaborative leadership skills on the success of the collaborative process and community-level change. Importantly, the findings presented here can be applied to grantmaking strategies, as we are testing a model that addresses the main challenges noted in the literature around collaboratives - namely, the issues related to accountability, relationshipbuilding, and performance.We first discuss the need for leadership development in collaborations, then discuss TOAC, which incorporates collaborative leadership development as a key component of collaborative success; and then describe how TOAC is implemented through LAP. We then summarize our research and findings and make specific recommendations based on those findings. We point to the most important aspects of collaborative implementation in relation to performance, and inform grantmakers on the most essential areas for investment. We provide examples from one LAP implemented in Marion County, Indiana, to illustrate how these components can be put into practice.Collaborative Leadership Development: A Necessary Ingredient for SuccessCollaboratives are created when two or more organizations join to share information and resources in an effort to create solutions to social problems that could not be achieved by organizations working independently (Bryson, Crosby, & Stone, 2006). Collaboratives are often very loosely structured, without formal leaders and with members typically volunteering to work across sectors and represent their organizations. …