This dissertation project is a three-phase mixed methods study aimed at understanding how early care and education centers make decisions about subsidy system participation, paying close attention to the influence of state policies and other factors amenable to policy intervention. Phase I is a mixed methods statewide study that examines how providers make decisions about accepting subsidies. In phase II, nationally representative data is used to examine predictors of subsidy density, or the proportion of children in a program using subsidies. Phase III uses a nationally representative sample of early care and education centers alongside state-specific subsidy policies to examine the unique influence of subsidy policies on provider participation in the subsidy system. This dissertation provides useful insights into how to implement state policies and practices that could incentivize providers’ participation in the subsidy system, and as a result better serve families from low-income backgrounds. (author abstract)