Fuel cells represent a promising clean and efficient energy conversion technology for urban bus fleets throughout the world. Currently, UNDP/GEF-supported demonstration projects are underway in five countries: China, Brazil, Egypt, India, and Mexico. At the end of the GEF project’s lifetime, it is expected that the FCB initiative will have helped to bring fuel cell buses closer to commercialization and make them more attractive to other donors, and—ultimately—to private investors. This report presents an approach to evaluating investments in FCBs in a subsequent commercialization phase. It provides a policy framework to assess the country context favoring the continued support of multilateral institutions and other sources of investment in fuel cell buses.