In 2002, the Dept. of Defense (DoD) began developing and rapidly fielding a global Ballistic Missile Defense System (BMDS) composed of elements that include radars, interceptors, and command and control systems. These elements are envisioned to be linked together to defend against a broad range of ballistic missile threats. In 2009, DoD began a broad review of missile defense policy and strategy intended to reassess the BMDS and set direction for the future. This report reviewed the extent to which DoD has: (1) identified the types and quantities of elements and interceptors it needs; and (2) established the units to operate elements that have been put into use. The author reviewed studies and other documents from the Missile Defense Agency.