To describe the research behind Practice-Based Coaching, a team of researchers from the National Center on Quality Teaching and Learning (NCQTL) built on and extended a thorough review of the early childhood professional development literature conducted by Snyder and colleagues (2012). The goal of the NCQTL review was to: 1. Examine what recent research says about coaching for practitioners who work with young children. 2. Examine what recent research says about key components of the Practice-Based Coaching model. 3. Discuss why Head Start programs might consider Practice-Based Coaching as an essential part of professional development. (author abstract)