The rapid progress in medical technology makes it unavoidable to ration health care. In the discussion how to ration many people claim that principles of justice in distributing scarce resources should be applied. In this paper we argue that medical resources are not scarce as such but scarcity is a necessary by-product of collective financing ... arrangements such as social health insurance. So the right question to ask is the determination of the benefit package of such an institution. Hartmut Kliemt is currently involved in a commendable interdisciplinary research project in which principles of `prioritization' of medical care are studied. This contribution adds a specific perspective to this endeavour: we ask how the goal of distributive justice can be interpreted in this context and compare different approaches to implementing `just' allocation mechanisms.