Learning networks, such as a community of practice, can be an important way for planners to gain access to, and power in, new professional knowledge domains. In this manuscript, the authors develop, implement, and evaluate a community of practice model for planning education and practice in energy and sustainability planning. The authors find that although this active, learner-centered method helps enable flexible, self-directed study for those learning new content, there is a strong need for leadership in heterogeneous learning networks to help participants overcome problems created by social position and structuration within the network. New knowledge formation within learning networks ultimately challenges some of the planning profession's fundamental assumptions about the validity of "moving knowledge into practice" in contexts with uncertainty.