This chapter describes Multi-tiered Systems of Support (MTSS), with a specific focus on Response to Intervention (RTI) and Positive Behavioral Interventions and Supports (PBIS). When outlining MTSS, authors address how MTSS evolved as well as operating characteristics of the framework. MTSS is an prevention-based framework for enhancing the development and implementation of a continuum of evidence-based practices to achieve academically and behaviorally important outcomes for all students. It can be designed and implemented to promote racial equity and healing in schools and is grounded in and shaped by a number of foundational influences. These influences include (1) supporting youth with disabilities and special education; (2) curriculum-based measurement and precision teaching; (3) teacher consultation and support; (4) prevention science; (5) behavioral sciences; (6) evidence-based practices; (7) direct instruction; and (8) innovation implementation research. School counselors can use MTSS to address root causes of discipline disparities and explicitly integrate action to advance racial equity into MTSS' implementation. This chapter discusses the rationale for why this work is critically important, and how to leverage MTSS work to achieve needed change. [This is the in press version of a chapter that will be published in: "The School Counselor's Guide to MTSS. 2nd Edition," edited by E. Goodman-Scott, J. Betters-Bubon, J. Olsen, and P. Donahue, Routledge.]