Although a number of studies have examined ECEC costs, few have taken up the questions of how child care cost burdens reflect and contribute to income inequality. Our review of the literature suggests that, although poor families spend less in absolute dollars on child care than more-affluent families, this is largely due to differences in their use and mode of care. Differences in costs to families are dwarfed by the disparities in incomes, with the result that ECEC expenses impose particularly steep financial costs on low-income families. We estimate that the child care burden increased during the 1985 to 2000 period for all groups except the most highly educated, increasing the inequality in cost burden over time. The literature also suggests that child care costs make an indirect contribution to inequality by depressing maternal employment, particularly among less-skilled and single mothers. Despite large literatures on family structure, family labor supply, income inequality, child care policy, and child care arrangements and costs, very little is known about the interrelationships between these forces. Important questions for future research include: • Did child care burdens become more equal or more unequal as employment increased for married mothers and later for single mothers? • Have child care policies, such as Head Start, child care subsidies, and child care tax credits kept up with increases in maternal employment? And have the changes in policies ameliorated or exacerbated income inequality? • Do families with higher child care burdens choose lower-cost (and presumably lowerquality) child care options? Is maternal employment lower among these families with higher child care burdens, which perhaps contribute indirectly to income inequality?.