The purpose of the study was to understand current knowledge and implementation of a multitier system of support. The study focuses on tertiary interventions and uses input from teachers in a top education system who are responsible for implementing a Response to Intervention (RTI) framework daily. Sixty-three K-5 teachers were surveyed to determine understanding of an RTI framework, implementation of tertiary supports, and resources contributing to the teachers' knowledge of RTI. Virtually all responding teachers reported implementing RTI, but many teachers did not understood who should receive tertiary supports, what supports are evidence-based, where to find information about best practice, or that tertiary supports are always part of an MTSS. Implications for practice are discussed with strategies, resources, and quick tips for classroom implementation.