The purpose of this study was to examine elementary teachers' perceptions of the effectiveness of Response to Intervention (RTI) and Teacher Support Team (TST) within a Mississippi Gulf Coast school district. RTI models have gained popularity within the national education system. Schools are encouraged to implement RTI in efforts to improve the learning and achievement of all students, while meeting the requirements of the No Child Left Behind Act of 2001 (NCLB) and the Individuals With Disabilities Education Act of 2004 (IDEIA). With the change of educational policy, the role and function of teachers have changed. Understanding perceptions teachers might have towards implementing RTI can be beneficial for the successful implementation if RTI. This study examined teachers' familiarity with RTI and TST, level of training or adequacy, perceptions of RTI and TST effectiveness, perceptions related to special education, and influencing factors on decisions to refer students to TST. This study also examined teachers' perceptions of RTI and TST based on whether there was a full-time and part-time facilitator, area of certification, level of education, and years of experience. This quantitative study utilized the Bailey-Tarver survey which included four demographic questions, 21 Likert scale statements, and two multiple response questions. Descriptive statistics and Analysis of Variance (ANOVA) were used to analyze data from the survey. The results from this study indicated that there were no significant differences in teachers' perceptions of the effectiveness of RTI and TST based on whether the school had a full-time and part-time facilitator, level of education, and years of experience. However, there was a significant difference in teachers' perceptions of RTI and TST effectiveness based on area of certification. The results of this study also provided recommendations for the school district to plan for effective implementation of RTI in the future. The recommendations encourage school leaders to offer more in-service or teacher training, find ways to accelerate or simplify the RTI/TST process, and provide full-time RTI facilitators and effective interventions. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]