Government-sponsored development finance institutions (DFIs) have become key delivery mechanisms for poverty alleviation and the exercise of soft power. A reformed and fully equipped U.S. DFI would directly provide billions of dollars in additional energy sector investment and would catalyze many billions more in private investment. With earnest and bipartisan consensus building around U.S. development finance reform, this policy brief seeks to summarize the importance of energy sector finance in the context of development and foreign policy, to outline the energy financing gaps in emerging markets, and to analyze how the new tools and authorities proposed under the Better Utilization of Investments Leading to Development Act (BUILD Act) legislation would equip the U.S. DFI to respond to those financing needs.