This article compares two sets of annual population estimates for the state of New Mexico and its counties, from 2001 through 2006: the U.S. Census Bureau Population Estimates Programs intercensal estimates, and alternative estimates from the UNM Bureau of Business and Economic Research Population Estimates Program. The author describes how the Census Bureau undercounted the NM population in the 2000 decennial census, with a resulting loss of federal funding for state social programs. For this reason the state has funded the Census Dissemination and Demographic Analysis Project; the BBER-Population Estimates Program has been tasked with providing population data with better accuracy. He then explores the different methodologies used for the two data series and discusses how the Census Bureau\u27s use of administrative records, such as birth and death rates (known as the \u27cohort-component\u27 model), may lead to an underestimation of the NM population. The author argues that BBER-PEP\u27s housing unit-based procedure is more accurate. Illustrated with tables and graphs.\u2