BACKGROUND: Collaborative forms of organizations such as multisectoral health care alliances play an increasingly prominent role in the U.S. health care system. A key feature of these organizations highlighted in previous research is leadership, yet little research has examined what happens when there is a change in leadership. PURPOSE: The aim of this study was to examine the relationship between leadership transitions in an alliance and member assessments of the benefits and costs of participation, indicators of the value that members derive from their involvement in the alliance. METHODOLOGY/APPROACH: The study used quantitative data collected from three rounds of surveys of alliance members participating in the Robert Wood Johnson Foundation's Aligning Forces for Quality Program. Qualitative interview data supplemented this analysis by providing examples of why leadership transitions may affect participation benefits and costs. FINDINGS: Quantitative analysis indicated that alliance members who experienced a change in leadership reported both higher and lower levels of participation benefits and costs, depending on the type of leadership change (i.e., alliance leader vs. programmatic leader). Qualitative analysis suggested that the scope of responsibilities of different types of leaders plays an important role in how members perceive changes. Likewise, interviews indicated that timing influences how disruptive a leadership transition is and whether it is perceived positively or negatively. PRACTICE IMPLICATIONS: Leadership transitions present both challenges and opportunities; whether the effects are felt positively or negatively depends on when a transition occurs and how it is handled by incoming leaders and remaining members. Furthermore, different types of members report higher levels of participation benefits and lower levels of participation costs, suggesting that efforts to maintain a sense of alliance value during times of transitions may be able to target certain types of individuals.