To explore issues surrounding re-consenting youth in longitudinal studies as they reach legal adulthood interviews were conducted with 46 parents plus 13 autistic teens enrolled in the Simons Foundation Powering Autism Research for Knowledge (SPARK) study. Qualitative analysis focused on family sensitivities regarding guardianship decisions, transition concerns, and the re-consenting process. Questions regarding guardianship were difficult for parents unsure of a teen's future status. Mothers were key facilitators of re-consenting for soon-to-be-independent teens. As legal adulthood approached, parents were willing to assist teens with re-consenting but needed support, asking for multiple contacts, transition resources, and explanatory materials from the research team. Most teens were not cognizant of SPARK but willing to continue participation once made aware.