Rosales-Ruiz and Baer first wrote about the concept of behavioral cusps in 1996. However, it wasn't until the publication of a JABA article the next year (Rosales-Ruiz and Baer 1997) and a follow-up article by Bosch and Fuqua (2001) that the idea begins to spread throughout behavior analysis. A behavioral cusp is a special type of behavior change because it brings the organism in contact with new contingencies that have even more far-reaching consequences. The concept of the cusp has been both theoretically and pragmatically useful for the field of behavior analysis. In practice, the concept of the cusp helps guide the selection of target behaviors. In theory, it contributes significantly to our understanding of the way that behavior changes. This presentation will illustrate the concept of the cusp and distinguish it from other types of behavior change, such as generativity, and types of behavior, such as pivotal behaviors. It will also highlight some of the developments that have helped advance the concept of the cusp over the last 20 years and discuss the theoretical importance of the cusp concept.