Purpose: The primary purpose of the proposed project is to investigate the efficacy of Tier 1 and Tier 2 interventions delivered through a Response to Intervention (RTI) framework for children with attention-deficit/hyperactivity disorder (ADHD). Further, for children who do not respond to initial Tier 2 strategies, the proposed study will assess which additional course of intervention is most effective: (1) enhanced Tier 2 strategies or (2) stimulant medication. The majority of youth with ADHD are in general education settings, whether classified as special education students or not. Thus, experimentally evaluating the efficacy of well-developed and evidence-based behavioral interventions within a problem-solving framework such as RTI would significantly inform practice within school-based behavioral intervention teams. Project Activities: This study will employ a sequential multiple assignment randomized trial design (SMART). Prior to the beginning of the academic year, students will be randomly assigned to one of two conditions: (1) Business as Usual in which children receive whatever sequence of academic supports and interventions their teachers, school, and parents would typically put into place throughout the entire academic year and (2) an RTI approach to begin with Tier 1 classroom-wide management strategies with opportunities to add Tier 2 strategies for youth who do not respond to the initial Tier 1 approach.