Prior research has found that children with intellectual or developmental disabilities (IDD) may experience poor quality care and are at risk for adverse events, but less is known about risk among adults with IDD. Using data from a nationally representative database, the authors compared hospitalizations due to adverse medication events among adults with IDD compared with the general adult population and found that adults with IDD were at a significantly greater risk of having a hospital admission due to an adverse event (odds ratio, 1.28).