This paper reports on empirical research into the organizational and process changes necessary to implement large-scale reengineering using COTS. The research goal is to identify how these changes can be effected within the context of the existing United States Department of Defense acquisition management, requirements management, and planning, programming, and budgeting systems. While this effort is still in its early stages, initial results indicate that there are significant challenges in developing and defending budget inputs to support an evolutionary COTS-oriented acquisition model. At the same time, recent changes in acquisition constraints and other mitigating circumstances are being exploited to improve the likelihood of success.