Early retirement is predominantly considered as the result of incentives set by social security and the tax system. But people seem to retire early even in the absence of such distortions, as the Swiss example demonstrates. We look for determinants of early retirement, in particular the role of lifetime income and family status, using individual data from a selection of Swiss pension funds. Our findings suggest that affordability is a key determinant in retirement decisions: more affluent men and – to a much smaller extent – women tend to leave the work force earlier. The fact that early retirement has become much more prevalent in the last 15 years is another indicator for the importance of affordability as Switzerland’s funded pension system has matured over that period leading to higher effective replacement rates. We also find sizeable differences in retirement behaviour across marital status. These may be explained by a constrained rational choice based on differential mortality and the desire of couples to coordinate their entry into retirement.