In the wake of the Seebohm reforms of the personal social services, a number of studies were carried out in the 1970s to explore the role of frontline professionals in identifying and meeting social need. A common ®nding was that social workers behaved like``street-level bureaucrats'', using their discretionary authority defensively to manage an otherwise overwhelming workload. In the 1990s, top-down assessment and care management systems were put in place as part of community care reforms. Their aim was to reduce the scope of professional discretion so as to standardize responses to need and control demand according to resources available. In this paper, the authors consider the success of new systems in controlling``bottom-up'' decision-making by drawing on a recent empirical study of needs assessment practice in three types of social work team. They point out that the assessment practice of those teams facing the highest bombardment rates was most obviously criteria-driven, reinforced by the use of new technology. Rather than creating informal stereotypes to manage demand, social workers could mobilize legitimate forms of rationing to protect their time and other resources. Yet the sense of professional identity, the level of frontline autonomy, and the ways in which this was exercised, varied across the different types of team. The authors conclude, therefore, that the scope of discretionary space available to frontline staff in social services departments, and the practices to which it gives rise, are empirical questions only adequately addressed by methodologies able to connect with``bottom-up'' decision-making.