The purpose of this qualitative case study was to gain a deeper understanding of experiences of teachers working within a co-teaching model with upper aged elementary special education student populations. Cultural-historical activity theory (CHAT) provided the theoretical lens that revealed the key aspects associated with experiences of general and special education teachers working within a co-teaching model. A qualitative study approach was used to ascertain the experiences of general and special education teachers working within a co-teaching model with upper aged elementary students (grades 3 through 5) in a public education setting in the northern suburbs of Boston, Massachusetts. This research addressed a literature gap not previously scrutinized regarding the implementation of this change in practice from a traditional pull out model for students with special education needs. An analysis of teacher interviews, identified four major themes that impact the implementation of co-teaching and the outcomes of such a practice: School culture with a focus on collaboration, a desire for professional growth, a genuine respect for least restrictive environment expectations set forth in IDEA, success or outcomes. The results of this case study indicate that the overall coteaching experience is professionally rewarding and has a positive impact academically as well as socially for special education student populations. The findings from this study are presented to inform educators, administrators, and parents of the practices of successful implementation as well as potential positive outcomes for students and professionals working and learning in co-teaching environments.