Middle-aged adults engage in support exchanges with generations above and below. This study investigated (a) how support to one generation is associated with support to the other and (b) factors accounting for whether parents or offspring receive more support in a family. Middle-aged adults aged 40-60 years (N = 633) completed telephone interviews regarding their relationships and support exchanges with each grown child and living parent. Multilevel models revealed that most participants provided more support to the average grown child than to the average parent. Yet, a proportion of the sample reversed this pattern, providing more support to parents. Mediation models revealed that middle-aged adults provided greater support to offspring because they viewed offspring as more important than parents and offspring had greater everyday needs (e.g., being a student, not married). Parental disability accounted for greater support to parents. Discussion integrates solidarity theory, developmental stake, and contingency theory. Most middle-aged adults provide more to grown offspring than to parents, consistent with their greater stake in their progeny. Middle-aged adults also respond to crises (i.e., parental disability) and everyday needs (i.e., offspring student status) in providing intergenerational support, in accordance with contingency theory.