The U.S. Department of Energy's Office of Electricity Delivery and Energy Reliability (DOE OE) is developing a better understanding of the Smart Grid vendor ecosystem and marketplace, and is evaluating the impact of American Recovery and Reinvestment Act of 2009 (ARRA) funds on this marketplace. DOE OE has identified and classified the core Smart Grid vendors, assessed the overall market size and networks of vendors in the Smart Grid domains, and assessed the economic impacts of ARRA investments on these different markets. The key objective of this study is to understand the flow of funds through the Smart Grid projects and the associated vendor ecosystem that benefit from ARRA Smart Grid funds and to gain a better understanding of the associated economic impacts of the Smart Grid investments on the broader economy.