Previous studies of maternal employment have focused on marital status differences, but the rise in nonmarital cohabiting parenthood problematizes the simple dichotomy between married and unmarried mothers. Theory and previous research yield mixed predictions as to whether cohabiting mothers’ employment will more closely resemble that of married mothers or lone unmarried mothers. Using data from the Fragile Families and Child Wellbeing Study, I examine how maternal employment varies across family structures (married parents, cohabiting unmarried parents, and lone unmarried mothers) in the five years after a birth for mothers living in urban areas in the United States. Descriptive statistics show few differences in maternal employment patterns by family structure. Controlling for human capital, however, I find that cohabiting mothers return to work earlier and work more than married mothers. Cohabiting mothers and lone mothers show very similar employment patterns. Additionally, cohabiting mothers who later marry have employment trajectories that are similar to married mothers, whereas married mothers who divorce increase their employment hours. Family characteristics, partner characteristics, and gender attitudes do not explain employment differences between married and cohabiting mothers. I speculate that cohabiting mothers work more than married mothers as a hedge against economic deprivation given high union dissolution rates for cohabiting couples.