Using a systems approach, this paper explores the impact of devolution on additional learning needs (ALN) policy in compulsory phase education. Focus is placed on ALN/SEN Codes of Practice, the schools curriculum, teacher training, and the work of education inspectorates and tribunals. Analysis reveals that the move to quasi-federalism in the UK has led to a raft of territorially specific policies and resulted in contrasting legal rights for pupils and parents. The prevailing policy discourse is one of equality, inclusion and informed choice. Against this background, and with a number of reforms ongoing, there is evidence of progress in embedding measures to address ALN in the respective education systems. Notwithstanding this, analysis of the first decade of devolved policy and practice also reveals a number of shortcomings and challenges, including limitations in data-gathering and staff training--as well as questions about the level of cohesion between the three elements of education provision identified by systems analysis.