In an RtI/MTSS framework, resources are allocated in accordance with students' needs. This framework is usually shown as a multi-tiered model like the one below and involves more and more intense instruction and interventions across the tiers. The level of intensity of instruction and interventions a student receives is determined by how he or she responds to the instruction and/or intervention. Like the model shown below, Illinois’ RtI/MTSS model has three tiers.
Students may move fluidly among the tiers as a result of their response to the instruction and interventions they receive. For example, if data show progress, a student can move from Tier I to Tier II and back to Tier I within a relatively short period of time. It is also important that students receive the types and levels of interventions they need when they need them. Accordingly, movement across the tiers is not necessarily sequential. For example, a student with significant gaps in performance may immediately require intensive Tier 3 interventions and would, therefore, not receive Tier 2 interventions prior to Tier 3.