One of four being published on a five-state project on the dynamics of child care subsidy use, this report provides a detailed look at families receiving child care subsidies in Illinois, Maryland, Massachusetts, Oregon, and Texas, and the factors associated with length of subsidy receipt and provider stability. Data were collected and analyzed by a team of policy and methodology experts brought together through the Child Care Policy Research Consortium. State policy data were collected through document reviews and interviews with key informants. Micro-data were obtained from state child care subsidy administrative systems. Payment record files were also obtained for services during 24 calendar months in each state. Among the major findings is that the exercise of policy discretion at the state level has produced very different child care subsidy programs. The populations served in the various subsidy systems differed by income, the proportion of subsidized families that were employed, and the proportion mixing work and welfare. States also varied in the types of services provided to subsidized families and children. The length of children's subsidy receipt was short in all states. Within states, the length of subsidy receipt varied with some family characteristics, and there was considerable reentry into the subsidy system. Most children with short periods of subsidy receipt had a consistent provider. Subsidy receipt periods were influenced by the interactions of child care subsidy, TANF, and regulatory policies rather than by any single child care policy. The report concludes with a discussion of the implications of the findings for research and policy. Two appendices provide information on the data, measures, and analytic approaches and on additional state child care subsidy policies. (Contains 33 endnotes.) (KB)