In the Original Investigation entitled “Nocturnal Rapid Eye Movement Sleep Latency for Identifying Patients With Narcolepsy/Hypocretin Deficiency” published in the July 2013 issue of JAMA Neurology (2013;70:891-902. doi:10.1001/jamaneurol.2013.1589), incorrect information appeared in Table 2 and the Author Affiliations section. In Table 2, in the row “NPSG REML ≤15 min, No. (%),” the results for Comparison 4 should be 55 (46.6)e in the “Patients With Low CSF Hcrt Levels” column and 21 (17.8) in the “Patients With Normal CSF Hcrt Levels” column. In the row “NPSG TST, mean (SD), min,” the results for Comparison 4 should be 423.3 (69.0)  in the “Patients With Low CSF Hcrt Levels” column and 420.1 (69.4)  in the “Patients With Normal CSF Hcrt Levels” column. In the Author Affiliations section, the affiliations for Drs Poli and Plazzi should have been “Sleep Disorders Center, Department of Biomedical and Neuromotor Sciences, University of Bologna and IRCCS Istituto delle Scienze Neurologiche, Bologna, Italy.” This article was corrected online.