This chapter investigates what the old owe the young, distinguishing this question from two others, namely, what do parents owe their children, and what does one generation owe other generations? Four possible approaches are explored: 1) the old owe the young no more than any person owes any other person; 2) intergenerational equity; 3) allocation of resources according to Norman Daniels' prudential life-span account; 4) neo-Aristotelean accounts exploring either basic goods, or the virtues fitting for old age. It is argued that none of the approaches provide a complete answer, but that any plausible answer must recognise the existence of mutual obligations such that we cannot definitely determine what the old owe the young without also (partly) determining what the young owe the old.