This panel presentation describes how systems thinking and complexity-aware approaches inform the implementation and evaluation of an organizational capacity development intervention, USAID’s Expanding Monitoring and Evaluation Capacities (MECap) task order. The first presentation introduces systems principles concepts and explains how MECap’s implementation draws on these principles. The second presentation describes how MECap uses three complexity-aware approaches (outcome harvesting, social network analysis and success case method) to evaluate its fellowship program and it clinics. The third presentation explains how evaluation findings inform MECap's management and contribute to learning about organizational capacity development.