Child-care assistance is a critical safety net program that directly benefits families and society. But short spells and program churning raise concerns about the effectiveness of the child-care subsidy program to support stable employment and contribute to long-term family economic stability. On the basis of data that link administrative child-care assistance records with survey data on a sample of subsidy recipients in Illinois and New York, we examine demographic, employment, child-care, and subsidy program characteristics associated with the risk of experiencing child-care subsidy instability. As we hypothesized, these factors relate to exit risk, confirming and extending past research on determinants of subsidy instability. The study contributes new policy-relevant knowledge about how employment instability and public benefit rules and practices shape clients' program experiences and in turn how subsidy (in)stability may operate as a mechanism through which stable employment and economic security are ultimately achieved or threatened. (author abstract)