Why Co-Teaching? In theory, co-teaching combines the resourcefulness, expertise, and passion of two professional educators working side by side to create a gestalt-like learning environment using a variety of collaborative models ranging from “team teaching” to “one teach, one observe.” In practice, the use of co-teaching has experienced both highs and lows—the lows often a result of personal and/or teaching style clashes that have less to do with one or both teacher’s professional expertise. Effective co-teaching is about collaborative decision-making throughout the school year that is built on trust and respect. This PD Byte explores the co-teaching model and offers a set of co-teaching prerequisites that, if implemented with fidelity, can have a profound impact on student learning in the classroom.