Despite the popularity of professional learning communities (PLCs) among researchers, practitioners, and educational policy makers, studies on PLCs differ significantly on the dimensions and capacities used to conceptualize them. Further, the interrelatedness of different dimensions and capacities within PLCs is not often well conceived nor examined in terms of learning at multiple (individual, team, school) levels. In an effort to address this gap, this study assesses the multidimensional, multilevel nature of PLCs using data from 992 teachers from 76 Dutch elementary schools. Findings indicate that professional learning communities within elementary schools can be conceptualized and assessed by 3 strongly interconnected capacities that are represented by 8 underlying dimensions. This conceptual structure empirically emerged as equivalent at both the teacher and school levels. By providing increased insight into the multidimensional, multilevel nature of the concept of PLCs, this article aims to add conceptual clarity to the study of PLCs in elementary education. (Contains 1 note, 3 figures, and 2 tables.)