The coteaching classroom has grown with the influx of special needs students in general education classrooms. New state and federal laws mandated the need for collaboration when instructing special education students, and middle school teachers in a Northern New Jersey school district are experiencing challenges with the implementation of coteaching in inclusion classrooms. The purpose of this qualitative case study was to explore teachers' perceptions of collaboration challenges that resulted from coteaching in the classroom. The key research question of this study involved general and special education teachers' lived experiences in relation to the inclusion classroom and their attitudes and beliefs that influenced them in the classroom. This study was guided by Vygotsky's zone of proximal development theory, which addressed the importance of socialization and the development of relationships among all learners. Purposeful sampling was used to select 7 general education and 7 special education teachers who had coteaching experience. Data were collected through semistructured interviews and field notes. Data were analyzed using thematic analysis. The results showed a need for additional professional development focused on the areas of teamwork, trust, and cooperative planning. Based on the findings, a 3-day professional development was created to increase teachers' growth and self-efficacy of the implementation of successful collaboration in the inclusion classroom. This professional development may bring about positive social change by providing coteaching teams with the guidance needed to implement the coteaching framework with fidelity. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]