An avoidance goal is an undesired state from which a person seeks to distance themselves. Though important for understanding behavior, avoidance goals have received less attention than approach goals. In this paper, we present a dynamic, formal model that provides a framework for describing and predicting the dynamics of avoidance goal regulation. We conduct a series of simulations to examine the dynamic pattern of behavior that emerges from the model when an avoidance goal is pursued in isolation and when an approach goal is also present. Two versions of the model were examined. In the first, the avoidance goal is regulated by a positive feedback loop. In the second, the avoidance goal is regulated by a negative feedback loop. We find that the positive feedback model produces a pattern of runaway behavior, even in a scenario where an approach goal is also present. By contrast, the negative feedback loop model produces a stable pattern of behavior that is more consistent with existing theory. The findings provide an important step toward theoretical parsimony by demonstrating that avoidance goal regulation, like approach goal regulation, can be understood using a negative feedback control system framework. We discuss new insights provided by this model and its potential to spark empirical research.