While many low-income families benefit form state childcare subsidies, researchers have shown that many families experience substantial subsidy instability or unstable and brief periods of time in the subsidy program. Subsidy instability has been shown to relate to a host of family and child factors, including childcare instability. I examine the relationship between state childcare subsidy instability and negative or positive child behaviors. I use linked survey data and administrative records from the Illinois-New York Child Care Research Partnership Study and employ ordered logit regression models to assess the connections between subsidy instability and child behavior. I also include several potentially related factors in the models, including material hardship and parenting stress. I find little evidence that child behavior and subsidy instability are directly related, or related to several potential moderators. My findings indicate that while subsidy instability has plenty of negative implications, it is not related to child behavior. Therefore, social policy that aims to address early child behavior, in particular for low-income children, should not focus on childcare subsidy instability but rather childcare type, for example. Further, my findings demonstrate that despite the well-documented negative effects of a host of forms of instability on child behavior, subsidy instability does not affect child behavior nor introduce significant negative behaviors.