One of the most notable changes in family formation experiences that has occurred in recent decades is the rising age at first marriage. Although this trend has been experienced across socio-demographic subgroups, the extend of the increase has not been similar for all women. Furthermore, few studies have examined the rising ages at marriage through multivariate analyses. Using six cycles of the National Survey of Family Growth, the current study aims to fill this gap in the literature by estimating ages at first marriage for four marriage cohorts spanning from 1978 to 2016. Preliminary results suggest that educational attainment does not account for cohort differences in the age at marriage. Furthermore, the factors that predict ages at marriage are not constant across marriage cohorts. We discuss these findings in a context of growing divergence in family formation experiences across socio-demographic groups, and propose avenues for future research.