Managing Department of Defense (DoD) research and development (R&D) portfolios is a challenging task today. Not only do defense R&D managers have limited resources to spend on pursuing new technologies, but there is also an active civil and commercial market for some technologies the DoD is interested in. How can the DoD better understand what areas it must pursue on its own and what areas it might be better off collaborating with non-DoD organizations? This article presents a straightforward approach for managing DoD R&D portfolios that can help DoD managers understand how their R&D efforts are allocated, and how they might more efficiently manage them to take advantage of scarce resources and technological capabilities elsewhere. After describing the approach, the authors illustrate it using the example of the basic research technologies' part of the U.S. Army's R&D portfolio.