Current educational reform mandates the implementation of school-based models for early identification and intervention, progress monitoring, and data-based assessment of student progress. This article provides an overview of interdisciplinary collaboration for systems-level consultation within a Multi-Tiered System of Support (MTSS) framework. The roles of school psychologists and school-based administrators are presented in relation to the implementation of MTSS practices within an implementation science model. The training and expertise of each discipline are highlighted related to respective aspects of implementation drivers (i.e., competency, organization, leadership). Functions of principals and school psychologists during team-based, problem-solving MTSS practices are described based on a problem-solving framework consistent with school-based consultation. Future directions for graduate training of school psychologists and principals and directions for consultation research are provided.