Administrative and survey data provide two sets of facts. A number of research efforts have begun to address this problem by linking survey and administrative datasets. This paper reports on a joint effort by the U.S. Census Bureau, university research centers, and state government to combine census survey data (2001 Supplemental Survey) with wage report administrative data, income assistance program data (TANF), and child care subsidy program data at the household and individual person levels. The primary goal of the research is to understand how participation in the child care subsidy program, when eligible, affects employment outcomes of parents. Another goal is to develop a model by which eligibility can be estimated. The paper will address legal, political, and technical challenges associated with such an effort and present the outcome.