Older parents of adults with intellectual disability are reported to be frequently isolated from the services designed to support their caregiving. The interaction between older parent caregivers' biographies and their involvement with the service system was examined. Parental status was predicted to be an explanatory mechanism for understanding the differential nature of their engagement with services. Analysis of interviews with 64 such caregivers of adults with intellectual disability revealed that their perceptions of their parental status were derived from a complex interaction of their values and beliefs, actions in relation to their adult child, constraints as well as resources available to them, and their relationships with service agencies. Implications for service delivery and directions for research are discussed.