The purpose of this study is to investigate a) longitudinal patterns of maternal postpartum alcohol use as well as its variation by maternal age at child birth; b) within maternal age groups, the association between other maternal characteristics and alcohol use patterns for the purposes of informed prevention design. Study sample consists of 3,397 mothers from the Fragile Families and Child Wellbeing Study representing medium and large U.S. urban areas. Maternal drinking and binge drinking were measured at child age one, three, and five years. We conducted separate longitudinal latent class analysis within each of the three pre-determined maternal age groups (ages 20–25: n=1,717; ages 26–35: n=1,367; ages 36+: n=313). Results revealed different class structures for maternal age groups. While two classes (NB [non-binge]-drinkers and LL [low-level]-drinkers) were identified for mothers in each age group, a third class (binge drinkers) was separately distinguished for the two older age groups. Whereas binge drinking rates appear to remain stable over the five years post-delivery for mothers who gave birth in their early twenties, mothers ages 26 and older increasingly engaged in binge drinking over time, surpassing the binge drinking behavior of younger mothers. Depression significantly increases the odds of being a NB-drinker for the 20–25 age group and that of being a binge drinker for the 36+ age group, whereas smoking during pregnancy is associated with subsequent binge drinking only for mothers ages 20–25. Findings highlight the importance of distinguishing risk factors by maternal age groups for drinking while parenting a young child, to inform the design of intervention strategies tailored to mothers of particular ages.