A study was conducted to explore the impact of professional development related to the individual education plan (IEP) process on teachers' understanding and practices in the Republic of Ireland (RoI). This paper reports on part of that research, focusing on teachers' collaborative practices in the IEP process. In the RoI, teachers working as special education teachers (SET) can avail of State-funded professional development through an award-bearing model provided by universities. The study combined survey of three cohorts of teachers who undertook this professional development course in one university with follow-up focus groups, observation and documentary analysis in five schools. Challenges to effective team functioning were identified in relation to the constructs of joint instructional work, communication, and values and ethics. Building on these constructs, this paper proposes a framework for developing competencies in collaborative practice for inclusion of students with IEPs with implications for practice and for teacher educators.