Ireland has a particular historical context in the delivery of public welfare services with a pervasive presence of NPOs, largely charitable religious organisations. In the area of intellectual disability services nearly ninety percent of State funded services are provided by such organisations. As these organisations have for the most part being exclusively involved in the delivery of services, that have become in the majority State funded, they exhibit mixed public sector and NPO characteristics. Building from a preliminary case study in the sector, this paper argues that effective planning and performance management in the delivery of intellectual disability services in Ireland has to navigate challenges in four organisational, process and service delivery fields: (i) the historical underpinnings and institutional nature of the organisations involved, (ii) the nature of the service being delivered and the characteristics of those receiving the service, (iii) decoupling in the strategic/performance management processes and (iv) the governance, organisational and stakeholder characteristics of hybrid service organisations. The paper builds a case for targeted research in each of these fields as a structured approach to the examination of planning and performance management in the sector.