While the negative effects of early‐life stress on children's developmental outcomes are well documented, we know little about how these processes unfold and which children are more susceptible to these exposures. In this article, I outline how studying the effects of early‐life stress on children's development can be advanced by considering how epigenetic processes may contribute to the emergence of children's behavior. The study of epigenetics can help pinpoint the mechanisms by which early‐life stress may affect developmental outcomes and identify which children may be most sensitive to the effects of these exposures. I conclude by highlighting the challenges inherent in studying epigenetics in children and offer possible solutions.