Abstract: Adult children make up half of the family caregivers of elderly individuals in the United States. Due to prolonged long-term care needs, family caregiving can significantly impact adult children’s labor supply and earnings trajectory. This paper provides empirical evidence that daughters bear the brunt of family care compared to sons due to lower opportunity costs and the role of gender identity norms. Motivated by this empirical evidence, I structurally estimate a model of strategic interaction between a daughter and a son who differ in wages and preferences for family care. I find that heterogeneity in preferences, reflecting the importance attached to family care responsibilities, explains most of the gender gap in family caregiving. I estimate that daughters face a 4.6% drop in lifetime earnings due to family caregiving compared to a 1.5% drop for sons.