Purpose: School leaders rely on a number of collaborative policy tools to address fiscal and governance issues. While prior research has examined the dynamics and implications of research-practice and public-private partnerships, this study addresses a third form of collaboration: interdistrict cooperative agreements. Method: We develop a unique data set to study the formation of interdistrict agreements formed among 333 public school districts in the state of Iowa from 2008 through 2017. Aimed at reducing costs and improving student outcomes, these agreements collectively reflect an intergovernmental network that develops through predominantly bilateral agreements. We examine the factors and mechanisms that can facilitate and hinder interdistrict collaboration through a stochastic actor-oriented model for analyzing panels of network observations. Findings: We find both transitivity and popularity to be positively associated with the inclination to form cooperative relationships. Further, school districts are more likely to collaborate with districts that have a: (1) greater number of enrolled students; (2) smaller percentage of students that receive free or reduced-price lunch; (3) higher student-to-teacher ratio; and (4) lower average teacher salary. Propinquity and homophily effects are present as well: between any two given school districts, the likelihood of collaboration improves as geographical distance and the absolute difference in district-level measures decreases. Implications: Understanding the antecedents of education network formation enables examinations of how network characteristics can reduce the cost of providing education or improve student outcomes.