On August 24 , 2012 , an employee in Kaiser Permanente ’s Northern California Region Recruitment department mistakenly emailed a list of former Northern California KP employees who left the organization between 1990 and 2006 to a person not authorized to receive the information . Some of these NCAL former employees have since returned to KP in various regions . This list contained , among other information , your name and Social Security number . No personal health information was involved . The unintended recipient who received the information has been extremely cooperative . Kaiser Permanente ’s IT Security conducted a detailed analysis to confirm that the recipient effectively deleted the information and that the information had not been further emailed or printed . As a result of our investigation , we believe it is highly unlikely that your information has been , or will be used for unlawful purposes . ;