The cyclically adjusted budget balance (CAB) plays a key role in the EU fiscal surveillance framework. It started off in a supporting role in the shadow of the headline defi cit and, before long, turned into the linchpin of the rules of the Stability and Growth Pact. The steep ascent was driven by high expectations which, with the passing of time, were only partly met. The everyday practice of the EU fi scal surveillance rapidly revealed a number of caveats of the CAB which, at times, hampered the effectiveness of fiscal surveillance. This paper provides a comprehensive review of the changing fortunes of the CAB in the EU fiscal surveillance framework. It portrays its main shortcomings and the way they are dealt with in practice.