Co-Teaching: The Professional Behind the M.A.S.K. is a compilation of personal experiences, research, and strategies that have increased the effectiveness of colleagues, mentors, and educators that labor in the co-teaching classroom. Co-teaching is a concept that teachers traditionally receive minimal training. Consequently, they are often unequipped to serve the needs of the classroom. The expectation is that the pair work collectively and the classroom experiences a new level of student growth. However, until this training is a reality in our schools and educational system, teachers should seek outside resources to better equip us for the journey. Tzivinikou (2015) says, "The collaboration of special and general education teachers is one of the most important factors related to the effectiveness of the education of pupils with special educational needs." The goal of TMS' guide is to help struggling co-teaching partners plan, implement, and work together as one cohesive unit. TMS' guide is practical information with immediate application. It is our hope that this guide will help you M.A.S.K. the inevitable. Manage the stress, Accept co-teaching as a valuable tool, Strengthen your relationships, and create the Keystones that will allow for personal growth.