We currently give absolute priority to medical interventions that save the life of individuals who are on the verge of death. Nobody in the UK is ever refused life-saving treatment unless it is unproven or ‘futile’. We do not take into account how much voluntary risk a person has taken on, their ability to pay, or even (in most cases) how expensive the therapies will be. If some curative intervention can provide a number of healthy additional years of life to a particular individual, it is provided. Prophylactic medicines, by contrast, are rationed according to cost, demand, and effectiveness. At present, rejuvenation therapies are viewed as elective, prophylactic, and inessential interventions, and for these reasons they are provided only at the patient's personal expense (if they are provided at all). If this policy is maintained as the effectiveness of rejuvenation therapies increases, disparities in lifespan will increase enormously. Consequently, economic inequalities will also increase, as wealth and power are concentrated in the hands of those who could afford rejuvenation at the outset. Considerations of justice will require that steps are taken to avert this outcome. However, if rejuvenation is expensive to provide, it will not be possible to provide it universally in order to avoid creating these inequalities in welfare. Inevitably, some therapies will need to be provided at the expense of others. Since rejuvenation therapies will ultimately offer many more years of life than traditional life-saving interventions, a problem emerges for existing principles of medical decision-making. Justice demands that all patients are due an equal standard of medical care. But if we measure medical care in terms of the amount of life it saves, or in terms of its cost relative to its effectiveness, or even in terms of its ability to save identified individuals rather than reduce statistical risk in groups (Hope 2001), rejuvenation will eventually be far more valuable than life-saving. More broadly, effective rejuvenation medicines will effectively erode the boundary between curative and prophylactic medicines, as well as the boundary between treatment and enhancement. The existing policy, in which life-saving medicines are prioritized, will become untenable even according to existing justifications. However, we presently have no moral framework for refusing life-saving medicine in favour of life-extending medicine. We will soon need new ways of allocating healthcare resources that will be consistent with the realities of a world with effective rejuvenation therapies. I suggest several strategies which might meet this challenge.