Women live longer than men, on average, but they have lower retirement wealth, lower expected social security benefits, and are more likely to be single and poor in old age. Some previous studies have concluded that women’s more conservative investing is a major factor leading to observed gender differences in retirement preparation, but current research does not strongly support that viewpoint. Nevertheless, there is substantial evidence of gender differences in social roles, psychology, and labor market experience that make it more difficult for women to save adequately for retirement. This chapter reviews the research on these differences and identifies potential policy solutions.