Problem and Objective: Transition to adulthood for young people with (IDD) is challenging for both youth and parents. Prospection, an important human adaptive tool and critical for independent living, involves constructing, encoding, and remembering the future. It may be jointly enacted between parents and young people as they discuss the future. This study identified and described evidence of prospective content in parent-youth conversations about the transition to adulthood. Method: This study involved the content analysis is of eight parent-youth conversations about this transition. Two mother-daughter, three father-daughter, and three mother-son dyads, representing a range of IDD diagnoses, provided 790 min of joint conversations and reflection on them. These conversations were examined for the following characteristics of prospection: simulation, reasoning about counterfactuals, constructing multiple possible futures, and episodic memory of the past. Findings: Among the four characteristics, simulation and episodic memory of the past were used most frequently and reasoning about counterfactuals the least. Giving advice and scaffolding were additional strategies that emerged from the data. Conclusion: Identifying how prospection may be fostered in joint parent-youth conversations provides a step toward future research.