We believe that increased private and public investment in helping low-income young children prepare for kindergarten is one of the smartest investments that we can make. These investments should support the outcomes that matter most--those that allow children to enter kindergarten ready to learn. This paper has not been intended as a road map either for our own investments or those of others. As the range and diversity of the opportunities described here make clear, there is no single path toward the outcomes we all seek. Rather, we have tried to highlight both the importance of promoting kindergarten readiness for our nation's children and the variety of opportunities available to donors who want to invest wisely towards this end. It is our hope that this paper will help reverse the pattern of systematic underinvestment by surfacing tangible high-impact opportunities that private philanthropists and their public-sector partners can pursue today. (author abstract)