The rule of rescue holds that special weight should be given to protecting the lives of assignable individuals in need, implying that less weight is given to considerations of cost-effectiveness. This is sometimes invoked as an argument for funding or reimbursing life-saving treatment in public healthcare even if the costs of such treatment are extreme. At first sight one might assume that an individualist approach to ethics—such as Scanlon’s contractualism—would offer a promising route to justification of the rule of rescue. In this chapter I argue that contractualism cannot endorse the rule of rescue, whereas a collectivist approach that appeals to group solidarity would offer support for rescue cases. The argument, however, has its limitations, and though solidarity is of central concern in shaping public healthcare, there are good reasons for not endorsing the rule of rescue as a moral basis for allocating scarce resources in clinical care.