Although schools generally provide safe environments, teachers, staff, parents, and students are concerned with the rising level of disruptive, antisocial behavior (Horner, Sugai, Lewis-Palmer, & Todd, 2001). Only a relatively small number of students in a school building engage in the most serious and/or chronic problem behaviors. However, these students account for about 50% of the incidents handled by office staff and dominate a majority of staff time (Lewis & Sugai, 1999; Sugai & Horner, 1994). Recent research recommends addressing individual student needs within a schoolwide discipline system. The purpose of this article was to provide an overview of individual student systems, identify guidelines for implementing a function-based model, and describe a case study of a district's attempts to build a comprehensive district-based individual student support systems cadre. (Contains 1 figure and 2 tables.)