The Census Bureau has historically grouped high school diploma holders along with those who hold “high school equivalent” credentials. Among these is the credential earned through successfully passing the General Education Development (GED) test. Interest in identifying those with GEDs has recently increased, in part from debate within the academic and federal statistical communities about the inclusion of high school equivalency degrees in the calculations of high school graduation, and because of the increasing concern that equivalency degrees are not truly equivalent in terms of labor market value and as a basis for future educational attainment (Heckman and LaFontaine, 2010; Murnane, Willett, and Tyler, 2000; Clark and Jaeger, 2006; Michel and Roy, 2006; Boesel, Alsalam, and Smith, 1998; Cameron and Heckman, 1993). This paper outlines the ways that the Census Bureau captures persons with alternative high school credentials, provides estimates of prevalence based on these different methods, compares these estimates to administrative records, and reviews the Census Bureau studies on the relative reliability of survey items on high school credentials.