Interlocal service delivery networks have become a prominent subject within the urban governance literature, with significant scholarly attention being focused on the political, legal, and demographic characteristics that influence an organization’s decision to join a collaboration network. However, despite being a theoretically significant factor, few analyses have examined the role that service-function type plays in shaping these networks. This research note replicates and extends previous tests of the hypothesized relationship between service-function type and network structure by relying on a comprehensive 25-year data set of interlocal agreements from the state of Iowa. Using hierarchical linear modeling, the positive relationship between networks of system maintenance service-functions and network centralization is confirmed after controlling for the significant moderating effect of time. This more-generalized finding enhances our understanding of when local governments use service networks to solve public problems and potentially carries important implications for the relationship between network governance and policy performance.