The addition of the 19-25 age range in the Special Educational Needs and Disability Code of Practice (2014) presents wide scale change in the post 16 education landscape. Organisational change is a well-established field of psychology and research suggests that the effective management of change is key to effect practice. Within a critical realist paradigm, this research employs a case study design to explore the views of professionals implementing Special Educational Needs and Disability policy reform. Qualitative semi-structured interview data was analysed using thematic analysis (Braun and Clarke (2006)). Implications for the Educational Psychology Service and central and local government are proposed, which take into account both supportive factors and potential constraints of implementing policy reform.