Children from low-income families face many social and economic disadvantages, and high-quality preschool can help to alleviate some of them. Is "preschool for all" the best way to extend preschool subsidies to unserved disadvantaged children? Fully funding such a policy would be costly, and it is likely that a significant minority of beneficiaries would be from relatively high-income families. A crucial policy issue is whether public resources ought to fund a universal or a targeted approach focused on extending coverage to unserved disadvantaged children. The case for preschool subsidies targeted to disadvantaged children is strong on both efficiency and equity grounds. The case for preschool subsidies for advantaged children is weak on both criteria. Most of the evidence shows minimal benefits of high-quality preschool for more advantaged children, thanks to the resources available to their families in the absence of subsidies.