Behavioral levels systems are commonly used in a variety of settings and are usually applied at the group level to promote socially desirable behavior and compliance with institutional rules. Despite their widespread use, however, there is surprisingly little empirical data supporting the effectiveness of these interventions. In addition, some researchers have suggested that such group-based interventions may not be consistent with laws mandating individualized educational programming. The current investigation examined the effectiveness of individualized levels systems for decreasing severe problem behaviors exhibited by 4 individuals with developmental disabilities. An individualized multilevel system was developed for each participant based on functional analysis and preference assessment results. These interventions were highly effective in decreasing problem behaviors for each participant. For 2 participants, a component analysis was conducted to identify the necessary components of the levels system. Generalization and care provider training were conducted for all participants. The results suggest that levels systems based on functional analysis and preference assessment results can be effectively generalized and implemented by care providers with good treatment integrity. This approach is presented as a potential alternative to the group-based levels systems that are described in the literature and commonly applied in the community.