Social Security Number Randomization

The Social Security Administration (SSA) changed the way Social Security Numbers (SSNs) are issued on June 25, 2011. This change is referred to as "randomization." The SSA developed this new method to help protect the integrity of the SSN. SSN Randomization will also extend the longevity of the nine-digit SSN nationwide.

The SSA began assigning the nine-digit SSN in 1936 for the purpose of tracking workers' earnings over the course of their lifetimes to pay benefits. Since its inception, the SSN has always been comprised of the three-digit area number, followed by the two-digit group number, and ending with the four-digit serial number. Since 1972, the SSA has issued Social Security cards centrally and the area number reflected the state, as determined by the ZIP code in the mailing address of the application.

There are approximately 420 million numbers available for assignment. However, the previous SSN assignment process limited the number of SSNs available for issuance to individuals by each state. Changing the assignment methodology extended the longevity of the nine digit SSN in all states. On July 3, 2007, the SSA published its intent to randomize the nine-digit SSN in the Federal Register Notice, Protecting the Integrity of Social Security Numbers [Docket No. SSA 2007-0046].

SSN randomization affected the SSN assignment process in the following ways:

• It eliminated the geographical significance of the first three digits of the SSN, referred to as the area number, by no longer allocating the area numbers for assignment to individuals in specific states.
• It eliminated the significance of the highest group number and, as a result, the High Group List is frozen in time and can only be used to see the area and group numbers SSA issued prior to the randomization implementation date.
• Previously unassigned area numbers were introduced for assignment excluding area numbers 000, 666 and 900-999.

These changes to the SSN may require systems and/or business process updates to accommodate SSN randomization.

If you have any questions regarding SSN randomization or its possible effects to your organization, please see the related Frequently Asked Questions or email your question(s) to ssn.randomization@ssa.gov.