Knowledge and understanding of foundational reading skills are critical in teaching both beginning readers and students who continue to struggle with reading in upper elementary grade levels. The purpose of this research study was to examine the essential knowledge and aptitude of teachers and the relationship between this knowledge and the ability to teach reading to struggling students as schools implement the Response to Intervention process. This mixed-method study utilized focus group interviews and a teacher survey that was composed of three components: teacher demographics, professional development experiences, and a teacher literacy knowledge assessment. Important findings from this study determined that teachers who possessed the highest levels of education had the best understanding of pedagogical literacy content knowledge; however, there was no statistical significance between the number of literacy classes or courses taken and teacher knowledge on the literacy assessment. Surprisingly, research data showed that novice teachers scored higher on the literacy knowledge assessment. Data analysis of this study, along with additional research cited in this study, led to several recommendations. First, school leadership should examine both teacher literacy knowledge and pedagogical knowledge within the school. Followed by provisions for providing explicit, ongoing professional development in the foundations of reading knowledge along with effective instructional practices as a requirement for all staff involved in carrying out interventions within the RtI process. This study could be useful for district and school administrators when planning for high quality professional learning in order to contribute to continuous school improvement. The results of this study indicate that teacher preparation can make a difference in the levels of literacy knowledge and in meeting the instructional needs of all learners. [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.]