The clinical activities that constitute longevity making in the United States are perhaps the quintessential example of a dynamic modern temporality, characterized by the quest for risk reduction, the powerful progress narratives of science and medicine, and the personal responsibility of calculating the worth of more time in relation to medical options and age. This article explores how medicine materializes and problematizes time through a discussion of ethicality-in this case, the form of governance in which scientific evidence, Medicare policy and clinical knowledge and practice organize first, what becomes "thinkable" as the best medicine, and second, how that kind of understanding shapes a telos of living. Using liver disease and liver transplantation in the United States as my example, I explore the influence of Medicare coverage decisions on treatments, clinical standards, and ethical necessity. Reflexive longevity-a relentless future-thinking about life itself-is one feature of this ethicality.