Objective: to understand the structure and dynamics of families in the late stage of the life cycle that have a member with intellectual disability. Method: qualitative research using the Calgary Family Assessment Model as methodological framework. The study had 38 participants, distributed into 10 families that had a member with intellectual disability and whose parents were elderly. The interviews were analyzed with content analysis technique. Results: the following analytical categories were evidenced: “living with intellectual disability”, “communication as a strategy for encounter”, “family isolation and the need for support” and “concerns about care in the future”. Conclusion: families in the late life cycle who had a member with intellectual disability are arranged in a structure that overloads a single caregiver (mother), has little support network, uses communication as an instrument for understanding themselves and the other, besides having difficulties in projecting the future.