In the Original Investigation titled “Association of Mental Disorders in Early Adulthood and Later Psychiatric Hospital Admissions and Mortality in a Cohort Study of 1 Million Men” published in the August 2012 print issue of JAMA Psychiatry (doi:10.1001/archgenpsychiatry.2011.2000), due to coding mistakes during programming, there were errors in the reporting of the number of men as having been diagnosed with some forms of mental disorder at the conscription examination in early adulthood. The original study finding remains unchanged after the correction of these errors. This article was corrected online.