Collaborations and partnerships have been highly touted as essential elements in the work of broadening participation in STEM. Whether the STEM education and outreach involves K-12 educators, higher education researchers and teachers, industry leaders, or community partners, the belief is that collaborative team-based approaches result in more effective STEM education programs, initiatives, and outcomes. The call to collaborate sounds great. However, equitable and truly collaborative partnerships can be quite complex to design, develop, implement, and evaluate. Who should consider initiating a multi-institutional STEM education and outreach collaboration? What are some of the potential pitfalls and unexpected possibilities of a multi-institutional collaboration? What processes are most effective when forming a collaborative STEM team? With these questions as a point of departure, we invite contributions to this session which provide insights on the very important but also very challenging work of establishing, implementing, and evaluating multi-institutional STEM education research and outreach programs.