This paper uses the 1998 Survey of Consumer Finances to identify the factors that determine whether an eligible employee elects to participate in a 401(k) plan and the magnitude of the employee’s contribution. The conclusion is that the most important factor affecting employees’ participation and contribution decisions is their planning horizon. Those with planning periods of less than two years are much less likely to provide for retirement than those who have a more long-term perspective. These results are consistent with other studies suggesting that employee education can have a major impact on retirement saving. On the plan side, the most important determinants are the availability of an employer match and the ability of employees to gain access to their funds before retirement through withdrawal or borrowing. In short, good information about the need for retirement saving and good plan design can significantly increase participation and contributions. The question is whether employers have the incentive to make this effort under the new safe harbor nondiscrimination provisions.