Co-teaching is a practice in which "two professionals co-plan, co-instruct and co-assess a diverse group of students. Both teachers provide substantive instruction to all students on a daily, consistent basis. Neither is considered the main teacher of the class; they are equals" (Murawski, 2008, p. 29). Unfortunately, co-teaching in practice is often characterized by one teacher handling most of the instruction and the other operating in an assistant role (Murawski & Lochner, 2009, 2010; Volonio & Zigmund, 2007). Co-teaching should also be characterized by the use of multiple models that facilitate small group instruction, which should increase student to teacher interaction and student engagement (Friend, 2014). A way to address these gaps is to provide co-teachers with ongoing coaching support (CEC, 2012). The goal of this study was to increase the quality of co-teaching through different levels of coaching to facilitate small group instruction through parallel teaching and increase student engagement. This study used a MTSS model with a multi-probe design to respond to the level of support co-teachers need, starting with peer coaching, then traditional coaching, and finally bug in ear (BIE) coaching. There were three sets of co-teaching pairs who participated. There was an intervention effect for all three pairs of teachers with peer coaching, the first tier of the intervention. Therefore, the other two levels of support were not needed as all participants met criteria in peer coaching. Additionally, there was an effect in increasing student engagement with peer coaching. These procedures can be used and adapted for future research in coaching co-teachers to improve their practices. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]