PurposeYoung adults with intellectual/developmental disabilities (YAIDD) are a vulnerable population during HCT due to their complex care coordination and adaptive needs, yet factors associated with transition preparedness are not well defined. We aimed to determine factors associated with health care transition (HCT) preparation satisfaction for YAIDD establishing care with an adult medical home. Design and methods408 YAIDD or their families completed the HCT Feedback Survey 2.0 upon establishing adult care. Logistic regression models were used to determine associations between a composite of six HCT Feedback Survey questions that most correlated with the 2019 National Survey of Children's Health transition questions. ResultsYADD who had HCT preparation visits with a designated HCT clinic were 9 times more likely to have met all six composite HCT criteria after controlling for the number of technologies required and race/ethnicity (adj OR 9.04, 95% CI: 4.35, 18.76) compared to those referred from the community. Compared to patients who were referred from the community, the odds of feeling very prepared versus somewhat or not prepared were 3.7 times higher (adj OR 3.73, 95% CI: 1.90, 7.32) among patients referred from a designated HCT program. ConclusionsYAIDD who participated in a structured HCT program prior to transfer to adult care experienced higher transition preparation satisfaction. Practical implicationsA structured HCT clinic model to prepare adolescents with DD for transition to adult care may improve HCT preparation satisfaction for this population.