Interagency collaboration (IAC) is mandated by federal legislation and is a well-established best practice in the transition literature. At the same time, there is limited research that examines the predictors of greater IAC, and the breadth of partners that secondary special educators collaborate with across school systems, service systems, and communities to support the transition process. Using a quantitative survey of 376 secondary special educators in a Midwestern state, we examined their IAC practices by documenting the characteristics of their social networks (i.e., diversity, communication patterns, and supports exchanged). Furthermore, we examined which malleable factors including network intentionality, collaboration self-efficacy, innovative action, and access to transition-focused professional development were associated with greater IAC. These findings provide a deeper portrait of transition-focused IAC and have implications for special educators and teacher preparation programs.