This research article investigates the causes and consequences of municipal institutional arrangements for the provision of resilient critical infrastructure in municipalities. The study explains how the municipal organizational robustness and external institutional dynamics moderate the relation between capacities, leadership, and local government investment decisions. We examine hypotheses on moderating effects with regression methods, using data from 345 Chilean municipalities over a nine-year period, and analyzing the evidence with support of qualitative data. Our results reveal that municipal organizational robustness—operational rules, planning, managerial flexibility and integration, and accountability—is the most quantitatively outstanding moderating factor. The evidence leads us to deduce that efforts to support local governments in the emerging policy domain of resilient critical infrastructure require special attention to the robustness of municipal institutional arrangements. The results are valid for countries where the local governments have responsibilities to fulfill and their decisions have consequences for the adaptation. Since one of the objectives of the Special Issue “Bringing Governance Back Home—Lessons for Local Government Regarding Rapid Climate Action” is to explore how action is enabled or constrained by institutional relations in which the actors are embedded, this study contributes to achieving the goal.