Agricultural research and development are at a crossroads. The close of the twentieth century marked changes in policy contexts, fundamental shifts in the scientific basis for agricultural R&D, and shifting funding patterns for agricultural R&D in developed countries. Even though rates of return to agricultural research are demonstrably very high, we have seen a slowdown in spending growth and a diversion of funds away from farm productivity enhancement. Together these trends will contribute to a slowdown in farm productivity growth at a time when the market has, perhaps, begun to signal the beginning of the end of a half-century and more of global agricultural abundance. It is a crucial time for rethinking national policies and revitalizing multinational approaches for financing and conducting agricultural research. The authors present and evaluate practical policy actions for revitalizing agricultural R&D in the United States and globally to meet global food demand in the face of climate change and other challenges in the decades ahead.