With any new initiative, stakeholder insights provide critical information that can aid in the execution of the project. Gathering stakeholder perceptions of a new initiative is particularly critical in schools where teachers' varied beliefs may influence outcomes. Recognizing and acknowledging beliefs may make the difference in adoption of new initiatives, such as Response to Intervention (RTI). Using case study design, this qualitative study collected teacher perceptions and understandings regarding the implementation of a district wide RTI model. The Stages of Concern (SoC) diagnostic dimension from the Concern-Based Adoption Model guided data analysis. Through deductive coding, several themes surfaced on the SoC continuum including concern for professional development, doubt of effectiveness, and leadership execution. The study provides insight for teachers, researchers, and school leaders on SoC during change and RTI implementation.