Positive behavior support (PBS) emerged in the mid-1980s as an approach for understanding and addressing problem behaviors. PBS was derived primarily from applied behavior analysis (ABA). Over time, however, PBS research and practice has incorporated evaluative methods, assessment and intervention procedures, and conceptual perspectives associated with a number of additional disciplines. Recently, there has been some confusion regarding the definition of PBS and, in particular, its relationship to ABA. In this article, it was noted that the practice of PBS and ABA, in some instances, can be indistinguishable but that important differences in definitions and emphases mandate an explicit distinction. The purpose of this article is to address some of the key points of confusion, identify areas of overlap and distinction, and facilitate a constructive and collegial dialog between proponents of the PBS and ABA perspectives.