Does board diversity or representativeness influence organizational performance? Though it is understudied in both the public and the nonprofit sectors, learning more about this critical subject can enhance organizational performance within highly collaborative settings. Community mediation centers, which rely on multiple public and private resources to meet their programmatic objectives, provide excellent case studies for analyzing the impact of different kinds of interorganizational linkages on organizational performance. A multitheoretic view incorporating agency, resource dependence, and stakeholder perspectives is employed through a national sample and a two-stage analysis using a logic model to test the cumulative impact of board characteristics and interorganizational relationships on organizational outcomes. Organizations’ collaborative capacity depends on several kinds of boundary-spanning activities, including network ties, revenue sources, and the number of stakeholder groups represented on the board.