A master file, the NUMIDENT File, is created each time the SSA assigns an SSN to an applicant. The NUMIDENT File contains information about the numberholder; such as, name, date of birth, place of birth, gender, parents' names and citizenship status. If there is a change in status; for example, a non-citizen naturalizes as a U.S. citizen, the numberholder must notify the SSA or the NUMIDENT File will not reflect the change in status. Most qualified applicants are issued one SSN. In rare circumstances, the SSA will assign more than one SSN to a numberholder.
The most common circumstance for multiple SSNs is when there is clear evidence the numberholder's SSN has been misused. The numberholder must have been disadvantaged by the misuse and the misuse effected the numberholder's record of earnings before a second SSN will be issued. When multiple SSNs are issued, the SSA must cross-reference each number to ensure proper credit is given for earnings.
A Lawful Permanent Resident (LPR) may apply for an SSN through a local SSA field office or through an Enumeration at Entry (EAE) process in agreements with DHS and the Department of State. A communication and failure of procedure to cross check with pending applications can result in non-citizens being issued more than one SSN.
Non-citizens receive one SSN via the Enumeration at Entry (EAE) process and the other by submitting an SSN application at an SSA office.
DHS issues non-citizens an Alien Registration Number (ARN). A non-citizen then uses the ARN to obtain multiple SSNs or more than one person uses the same ARN to obtain multiple SSNs.
See OIG, SSA, Non-citizens Issued multiple Social Security Numbers, December 2012 for a complete report.