In the Original Investigation titled “A Budget Impact Analysis of Gene Therapy for Sickle Cell Disease: The Medicaid Perspective,” which published online March 22, 2021, there was an error in the Introduction section. The third sentence in the fourth paragraph of that section should read: “A gene therapy using the same lentiviral vector received conditional approval from the European Medicines Agency in 2019 for the treatment of transfusion-dependent β-thalassemia.” This article was corrected online.