Caregivers of terminally ill patients are at risk for anxiety, depression, and social isolation. Social support from friends, family members, neighbors, and health care professionals can potentially prevent or mitigate caregiver strain. While previous research documents the importance of social support in helping end-of-life caregivers cope with caregiving demands, little is known about differences in social support experiences among caregivers at different life course stages. Using life course theory, this study analyzes data from in-depth interviews with 50 caregivers of patients enrolled in hospice services to compare barriers to mobilizing social support among caregivers at two life course stages: midlife caregivers caring for parents and older adult caregivers caring for spouses/partners. Older adult caregivers reported different barriers to mobilizing social support compared with midlife caregivers. Findings enhance the understanding of how caregivers' life course stage affects their barriers to mobilization of social support resources.