The 2002 reauthorization of the Elementary and Secondary Education Act (ESEA) contained provisions that expanded state and district accountability for improving all schools and increasing the learning and achievement of all students, including those who struggle to master basic skills in reading and mathematics. In 2011, the U.S. Department of Education waived certain provisions of the law in exchange for reforms by states related to four principles: (1) achieving college- and career-ready expectations for all students; (2) developing differentiated recognition, accountability, and support systems; (3) supporting effective instruction and leadership; and (4) reducing duplication and unnecessary burden. As of December 2012, the U.S. Department of Education had approved the flexibility plans of 35 states (including the District of Columbia). American Institutes for Research (AIR) has developed a series of Pocket Guides that provide research-based information to support state and district leaders in implementing ESEA flexibility plans. This particular Pocket Guide focuses on the implementation of reforms that feature applications of a research-based framework for response to intervention (RTI) to address the flexibility plan requirements. To prepare this guide, AIR researchers reviewed the 35 approved flexibility plans to identify policies and practices relevant to the use of a research-based RTI framework to improve student learning and achievement. This guide (1) explains the essential components of RTI; (2) describes the requirements for Principle 2; (3) discusses how applications of a research-based RTI framework address Principle 2 in approved plans; and (4) provides considerations, based on knowledge of rigorous RTI research, for the implementation of research-based RTI frameworks to address proposed reforms. The guide offers additional resources for states and districts that are interested in implementing a research-based framework.