This article examines the role of family structure in the financial support parents provide for their children’s college education. Data are from the Health and Retirement Study. We focus on aspects of family structure that affect parental support and estimate shared family variance in investments as well as within-family variation using a multilevel model. Family membership accounts for about 60% of the variance in payment of college costs. Small family size, living with both biological parents (compared to one biological parent and a stepparent), higher parental education, and having older parents are associated with greater parental expenditures.