The role of structural change in energy use patterns is evaluated using a recently developed data set based upon the NAICS codes for the United States. Shifts between 65 industries in the commercial, industrial and transportation sectors account for almost 40 percent of the reduction in the US economy’s aggregate energy intensity over the 1997-2006 period. Excluding the transportation industries, these shifts account for 54 percent of the total effect. These estimates are more than twice the magnitude of those due to shifts between five major sectors of the economy. Since all these estimates use the preferred Fisher index, the results are more likely due to the most recently available data than to methodological issues like the decomposition approach.