The purpose of this quantitative causal-comparative study is to examine differences in structured literacy knowledge between dyslexia interventionists at the therapy level, the teaching or practitioner level and dyslexia interventionists with training with fewer requirements than the aforementioned. Reading scores across the United States continue to report high percentages of students who perform below proficiency levels despite the implementation of policies and procedures to mitigate this. Through using a multitiered system of services, students may qualify for dyslexia intervention provided by individuals specifically trained for such services. Although research studies have revealed a lack of structured literacy knowledge in preservice teachers and educators, little research informs the knowledge levels of those providing intensive reading intervention. This study comprised 94 participants from dyslexia intervention programs across the United States: 49 participants from the therapeutic level, 22 participants from the teaching or practitioner level, and 23 participants from dyslexia interventionist training programs requiring fewer requirements than the previously stated programs. All participants completed the Basic English Language Knowledge test, with the data applied to a one-way analysis of variance. Results indicated significantly higher knowledge of structured literacy from participants in the therapeutic level programs than the other two types of programs. Recommendations include subsequent research with larger sample sizes and studies to investigate student progress when receiving training from different levels of dyslexia intervention. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]