A letter report issued by the Government Accountability Office with an abstract that begins "By law, GAO is directed to assess the annual progress the Missile Defense Agency (MDA) made in developing and fielding the Ballistic Missile Defense System (BMDS). GAO issued its latest assessment of MDA's progress covering fiscal year 2009 in February 2010. This report supplements that assessment to provide further insight into MDA's prime contractor performance for fiscal year 2009. Prime contractors track earned value management (EVM) by making comparisons that inform the program as to whether the contractor is completing work at the cost budgeted and whether the work scheduled is being completed on time. Our analysis of contractor EVM data included examining contract performance reports for 14 BMDS contracts, reviewing the latest integrated baseline reviews, performing extensive analysis of data anomalies, and conducting interviews with Defense Contract Management Agency (DCMA) officials--the independent reviewers of MDA contractor EVM systems.