Response-to-Intervention (RTI) is a federal policy designed to reform instruction by using a systemic three tiered model to support all students. Because RTI requires teachers to adapt to new roles and responsibilities, it is important to consider their perceptions. This study examines teachers' sensemaking of RTI utilizing a qualitative case study of one elementary schools implementation. This study employed focus groups, individual interviews, and observations with grade school teachers to investigate how teachers describe and make sense of RTI. Constant comparative analysis revealed three major themes: (a) RTI adoption and understanding of its purpose, (b) RTI implementation and teachers' practices, and (c) RTI resources and barriers. The conclusions were developed from the analysis of these findings through the theoretical framework of Organizational Sensemaking in an effort to explain how teachers made sense of the reform initiative. Teachers believed their professional identity was at stake with the district's adoption of RTI. Veteran teachers collectively believed that RTI was a special education driven reform and it should not involve them in changing their teaching roles. A pivotal factor in the sensemaking process was whether the principal provided time for teachers to make sense together and see connections between the RTI literacy components and their current teaching practices. In the process of making sense of RTI in the context of their school, teachers altered and changed the basic foundations of the state's RTI model. Teachers identified time, lack of staff, and quality professional development as barriers to implementing a Multi-Tier System of Supports consistently and effectively. The implications for school reform include providing RTI initiatives with strong principal leadership and sufficient time for teachers to make sense of the reform efforts.