School federations are groups of two or more schools operating under a single governance structure. The study reported in this article compared federations designed to raise performance in low-attaining schools against a matched sample of their non-federated counterparts. The findings are based on quantitative analysis of data collected in 2009-2010 from the National Pupil Database (NPD), combined with semi-structured interviews in a small group ("N"?= 5) of federations. The findings suggest school federations may offer an alternative way of thinking about school turnaround as a collaborative, interorganizational process rather than a mechanism for single organizational change.