Abstract We study how demand for health insurance responds to family formation using a unique panel of young Australian women. Our data allow us to simultaneously control for the influence of state dependence and unobserved heterogeneity and detailed information on children and child aspirations. We find evidence that women purchase insurance in preparation for pregnancy but then transition out of insurance once they have finished family building. Children have a large, negative impact on demand for insurance, although this effect is smaller for those on higher incomes. We also find that state dependence has a large impact on insurance demand. Our results are robust to a variety of alternative modelling strategies.