Because of the complexity and speed of environmental, climatic, and socio-political change in coastal marine social-ecological systems, there is significant academic and applied interest in assessing and fostering the adaptive capacity of coastal communities. Adaptive capacity refers to the latent ability of a system to respond proactively and positively to stressors or opportunities. A variety of qualitative, quantitative, and participatory approaches have been developed and applied to understand and assess adaptive capacity, each with different benefits, drawbacks, insights, and implications. Drawing on case studies of coastal communities from around the globe, we describe and compare 11 approaches that are often used to study adaptive capacity of social and ecological systems in the face of social, environmental, and climatic change. We synthesize lessons from a series of case studies to present important considerations to frame research and to choose an assessment approach, key challenges to analyze adaptive capacity in linked social-ecological systems, and good practices to link results to action to foster adaptive capacity. We suggest that more attention be given to integrated social-ecological assessments and that greater effort be placed on evaluation and monitoring of adaptive capacity over time and across scales. Overall, although sustainability science holds a promise of providing solutions to real world problems, we found that too few assessments seem to lead to tangible outcomes or actions to foster adaptive capacity in social-ecological systems.