Despite growing interest and investment in ecosystem services across global science and policy arenas, it remains unclear how ecosystem services - and particularly changes in those services - should be measured. The social and ecological factors, and their interactions, that create and alter ecosystem services are inherently complex. Measuring and managing ecosystem services requires a sophisticated systems-based approach that accounts for how these services are generated by interconnected social-ecological systems (SES), how different services interact with each other, and how changes in the total bundle of services influence human well-being (HWB). Furthermore, there is a need to understand how changes in HWB feedback and affect the generation of ecosystem services. Here, we outline an SES-based approach for measuring ecosystem services and explore its value for setting policy targets, developing indicators, and establishing monitoring and assessment programs.