Pre-print, Working paper: We study the optimal taxation problem in an economy composed of two-person households (men and women), where agents influence their own old-age dependency prospects through health spending. It is shown that the utilitarian social optimum can be decentralized by means of lump sum transfers from men to women, because women exhibit a higher disability-free life expectancy than men for a given level of health spending. Once self-oriented concerns for coexistence are introduced, the decentralization of the first-best requires also gender-specific subsidies on health spending aimed at internalizing the effect of each agent's health on the spouse's welfare. In the presence of singles in the population, the optimal policy requires also a differentiated subsidization of health spending for singles and couples. Finally, under imperfect observability of couples, the incentive compatibility constraints reinforce the need for subsidization of health spendings.