This report analyzes contracting for products, services, and research & development (R&D) by the Department of Defense (DoD) and its key components. In provides an in-depth look at trends in DoD contracting since 2000, and provides an initial picture of the impact that sequestration has had on DoD contracting and the supporting industrial base. This fourth edition of the DoD report updates reports from previous years and provides greater breadth of analysis. The report examines trends in DoD contracting, breaking down DoD contract spending by a variety of contract and vendor characteristics. The report then uses this data to address key policy questions related to DoD contracting.