This paper is one in a series that compares data from the American Community Survey (ACS) with data from the Annual Social and Economic Supplement (ASEC) to the Current Population Survey (CPS). This paper focuses on comparisons of national distributions of race between the 2004 ACS and the 2004 ASEC. In this analysis, we look for differences that are both statistically and substantively different, and for those found, offer possible explanations.