The development of information for adjustment of the 1990 decennial census conducted by the U.S. Department of Commerce is discussed. Policy guidelines for the adjustment decision, which have been the subject of litigation, as well as technical operational plans are outlined. These plans include projects to evaluate the matching process, the effects of missing data, the sensitivities of any proposed adjustment to statistical assumptions, and the quality of small area data. Associated methods of demographic analysis are discussed briefly, as is the role of the Undercount Research Steering Committee. (TJH)