This research study examined how school leaders internalize new state-level reading policy aligned with the body of research known as the Science of Reading and how they make sense of district expectations to make decisions for their school community and its impact on students at-risk for reading difficulty. The Ready to Read Act is a Maryland State policy that mandates the use of screeners for all Kindergarten through Grade 3 students. The policy also details expectations for monthly progress monitoring and teacher professional development. Using Improvement Science and Qualitative methodology, this study identified how technical, normative, and political dimensions of policy implementation impact leader sensemaking. This research also illuminated how participants apply gatekeeping strategies in relation to the dimensions of policy reform implementation and how these strategies mitigate or promote racialized practices in education. This research, which took place in one of the 25 largest urban school districts in the United States, explained how school principals' experiences and beliefs affect outcomes for students at-risk for reading difficulty. Lastly, this research provides implications for antiracist Instructional Leadership practices for policy aligned with the Science of Reading. [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.]