Children born to married parents have better health, behavioral, educational, and economic outcomes than children of unmarried mothers. This association, known as the “marriage premium,” has been interpreted as emerging from the selectivity of parents who marry and from a positive effect of marriage. The authors suggest that the positive effect of marriage could be contextual, emerging from the normativity of marriage in society. They test this hypothesis using the case of Chile, where marital fertility dropped sharply from 66% of all births in 1990 to 27% in 2016. The authors find that the benefit of marriage for infant health was large in the early 1990s but declined as marital fertility became less normative in society, to fully disappear in 2016. Multivariate analysis of temporal variation, multilevel models of variation across place, sibling fixed effects models, and a falsification test consistently indicate that marriage has a beneficial effect when marital fertility is normative and a weak effect when is not. Generalizing from this case, the authors discuss contextual effects of diverse practices and statuses.