AbstractCommunity management is a common approach to securing access to clean water for rural residents. Its failure to sustain water services over acceptable lifetimes has been well-documented, adversely impacting human health when users return to unimproved sources during system downtimes. The objective of this study is to identify effective strategies for improving the performance of community-managed systems. The quantitative system dynamics models were developed using monitoring data for Bolivia and Colombia to simulate typical performance as infrastructure ages and to test strategies to improve performance. The two models captured the performance behavior revealed from monitoring data and were driven by the same structure: two reinforcing loops and two balancing loops. Although a strategy to professionalize the service provider enabled them to meet or exceed the target performance threshold, external financial support alone was ineffective. The paradigm shift from fix-on-failure corrective maintenance to preventive maintenance enables systems to sustain high performance levels over time. The models are useful for understanding the underlying system structure driving performance of community-managed systems and designing high-impact interventions using model simulations.