Using data from the Fragile Families and Child Wellbeing Study this paper examines associations between family structure and economic trajectories during the first five years after a child's birth, paying special attention to non-traditional families. Among families with stable structures, married-parent families have the highest economic wellbeing, followed by cohabiting-parent families and then single mothers. Among unstable families, exits from marriage and cohabitation are associated with declines in mothers' economic wellbeing. Entering coresidential unions after a non-marital birth is associated with gains in single mothers' economic wellbeing, especially if those unions involve the child's biological father. Findings are robust across several measures of economic wellbeing including household income, income-to-needs ratios, and material hardship.