Since its inception in 1977, the Department of Energy has invested substantial sums in energy efficiency and fossil energy R&D. To monitor its effectiveness, the agency and Congress have, over the years, pursued evaluation of these R&D programs that focuses on its cost and benefits. Such evaluation, however, is difficult and must incorporate the full range of public benefits as well as what might happen if that R&D had not been funded by the federal government. To help address these challenges, and at the direction of Congress, DOE asked the NRC to develop a methodology for evaluating the prospective benefits of its fossil energy and energy efficiency R&D programs. Such methodology can be used to evaluate program management and funding decisions on an ongoing basis. This letter report provides an overview of the studies approach and how it differs from retrospective studies of this R&D previously carried out by the NRC.