The Department of Defense (DoD) has begun to phase out the printing of Social Security Numbers on identification cards. This change was implemented to protect the personal identity information of the cardholders.
Newly printed ID cards will have an 11-digit DoD Benefits Number (DBN) printed on the card. Similar to some commercial plans, the first nine digits will indicate the sponsor and the last two digits will identify each family member.
However, the health claims processing system still requires the sponsor's SSN to be the policy number, so be sure to obtain this information from the patient. This will eventually change over to the DBN and we will inform you when that happens.
Source: http://www.tricare.mil/ssn/Contractors.aspx.