This dissertation addresses the association between family support and work-family conflict in a unique but prevalent support context: when an employees parent provides non-custodial care for the employees child or children (grandchild care). Drawing from work-family theory and theories of intergenerational support, this study addresses two central questions regarding the link between social support and work-family conflict: 1) what is the direction of the association between parental support provision (grandchild care) and work-family conflict?, 2) does the association between parental support provision (grandchild care) and work-family conflict depend on the support context (i.e., caregiving challenges)? Participants included 360 working parents whose own parents provided grandchild care. Participants completed measures of grandchild care, work-family conflict, and caregiving challenges at baseline (Time 1) and one year later (Time 2). Using a cross-lagged panel design, results indicated that Time 1 grandchild care was significantly negatively associated with time- and strain-based family-interference-with-work at Time 2. However, Time 1 grandchild care was not associated with Time 2 work-interference-with-family. Contary to theories of intergenerational support, Time 1 work-family conflict did not predict Time 2 grandchild care. Caregiving challenges did not consistently moderate the associations between grandchild care and work-family conflict; however, caregiving challenges were positively related to Time 1 grandchild care and Time 2 family-interference-with-work. These findings support work-family theory and suggest that grandchild care can be a viable way for employees to reduce their FIW over time.