Students in alternative, residential, and correctional settings present challenges in the classroom and facility due to the complexity and intensity of their behaviors. In addition, the factors typically associated with these settings including crowding, inconsistency, and conflicting staff perspectives on education and discipline present challenges for the delivery of effective function-based intervention plans. Multi-tiered frameworks such as positive behavior interventions and supports (PBIS) provide mechanisms for organizing systems to be both proactive and responsive to students with the most challenging behaviors. However, the complexities of alternative, residential, and correctional settings require that PBIS be implemented with heightened intensity across tiers. This paper presents considerations for the effective implementation of Tier III systems and supports including function-based support planning (FBP). (Contains 1 table.)