This study examined the proportion of hospitalizations associated with adverse medication events (AMEs) for adults with intellectual and developmental disabilities (IDD) and adults from the general population in the United States using the 2013 National Inpatient Sample (NIS) dataset of the Healthcare Cost and Utilization Project (HCUP). Adults with IDD had greater odds of having a hospitalization associated with an AME than the general adult population. Unadjusted odds ratios (95% CI) for hospitalization due to any medication for IDD was 2.47 (2.31–2.65). In the multivariate logistic regression model, IDD was significantly associated, with an odds ratio of 1.28 (1.19–1.38). Adults who have IDD are at greater risk of having a hospital admission due to an AME.