On August 21 , 2012 , the 374th Medical Group ( 374 MDG ) at Yokota AB , Japan , discovered a potential compromise of patients ' protected health information ( PHI ) when , on or about September 22 , 2011 , a former 374 MDG provider mailed surgical reports he performed at the facility to his stateside address . These reports pertained to 438 patients and were intended for the American Board of Surgeons to maintain the provider 's board certification . Unfortunately , the package containing the medical information never arrived at his home and the United States Postal Service was unable to locate the package . The data elements involved in the documents include patient names , Social Security Numbers , dates of birth , diagnoses , descriptions and summaries of select procedures and operations performed by the provider between October 2007 and September 2011 . Upon discovery , the 374 MDG immediately initiated an investigation to determine the circumstances surrounding the loss and identify those who were potentially impacted . To mitigate this incident and prevent future compromises of this nature , the 374 MDG is currently reviewing their policies and procedures to assist providers with the board certification process . ;