Using an input-output “I-O” approach to estimating the economic impact of academic licensing and summing that impact over 20 years of available data for academic U.S. Association of University Technology Managers (AUTM) Survey respondents, the total contribution of these academic licensors to industry gross output ranges from $320 billion to $1.33 trillion, in 2009 U.S. dollars; and contributions to gross domestic product (GDP) range from $148 billion to $591 billion, in 2009 U.S. dollars. Estimates of the total number of person years of employment supported by U.S. universities’ and hospitals’ and research institutes’ licensed-product sales range from 1.268 million to over 4.272 million over the 20- year period. An explanation of the I-O approach is provided, and the assumptions used and the potential effects of the assumptions on the estimates are discussed. AUTM associated contributions to GDP, calculated using the I-O approach, are compared with U.S. GDP as a whole, and to selected industry, as defined by North American Industry Classification System (NAICS) codes, contributions to GDP. Factors affecting the AUTM contributions to GDP appear to differ from those affecting U.S. GDP as a whole, as well as from those affecting selected NAICS industry contributions to GDP.