The provision of before and after school care services, and the subsidy of these services through the Commonwealth Child Care Benefit, provide substantial support to many women in combining and balancing work and family. Relatively little analysis has been done in an Australian context, however, about the types of families who are using these services, and in particular, about usage and cost trends across time. We use unit record data from the 1999 and 2002 Child Care Surveys conducted by the Australian Bureau of Statistics to analyse formal child care usage and cost trends for school age children under 12 years of age. This period covers the introduction of the Child Care Benefit in July 2000, and our analysis allows us to draw some tentative conclusions about the possible impact of this new subsidy on real out-of-pocket costs of formal child care for school age children, and the use of such care. We use multivariate statistical techniques to examine factors that predict the use of formal care for school age children, and to examine the statistical significance of changes in usage patterns over time.