At Childrens National Health System ( Childrens National ) , protecting the security and confidentiality of patient personal and medical information is of the utmost importance . Regrettably , this notice concerns an incident involving some of that information . On December 26 , 2014 , Childrens National learned that certain employee email accounts had been potentially exposed in a way that may have allowed hackers to access information contained in those email accounts . This was a result of employees having received phishing emails and responding believing they were legitimate . This may have created an opportunity for unauthorized access to these individual email accounts from July 26 , 2014 to December 26 , 2014 . When we learned of this , we secured the affected email accounts and began an investigation into the phishing attack on our organization , including hiring an outside expert forensics firm . Through a comprehensive review of the affected email accounts , we determined that the information contained in the emails may have included patient demographic information such as names , addresses , dates of birth , and telephone numbers , and may have also included clinical information such as diagnoses , treatment received , medical record numbers , medical service codes or health insurance information . In a small number of instances , Social Security numbers were included . We reported the phishing attack to federal law enforcement and continue to work with them in their investigation . Importantly , neither patient charts nor our electronic medical records system were compromised . Only the discrete information contained in the email accounts was potentially affected . We have no evidence that this information in the emails has been misused or even accessed . However , in an abundance of caution , we began sending letters to affected patients on February 24 , 2015 , and have established a dedicated call center to answer questions patients may have . If you believe you are affected but do not receive a letter by March 15 , 2015 , please call 1 - 800 - 768 - 5812 , Monday through Friday , between 9:00 am and 9:00 pm Eastern Time . We recommend that affected patients regularly review the explanation of benefits statement that they receive from their health insurer . If you identify services listed on your explanation of benefits that you did not receive , please immediately contact your insurer . We deeply regret any inconvenience this may cause you . To help ensure that a similar issue does not happen in the future , Childrens National has re - enforced the educational training our staff receive regarding phishing or suspicious emails . We have also implemented enhancements to our existing technical safeguards and initiated a review of our systems to further protect patient information . ;