All Social Security cards have a series of numbers on the front and back. The ones on the back are for the card and the nine numbers on the front are for the account of the holders with the Social Security Administration.
Each citizen service number is unique and the agency has issued approximately 450 million cards since the programs were created in 1935. With an adjustment to the numbering scheme ten years ago, the nine-digit combination can continue to issue new songs for at least another 50 years.
Why are the numbers divided into three sets?
The Social Security program was established before the advent of modern computer technology. To assist record holders in their work, the three sets served a purpose: cataloging employee records of contributions and benefits. The first three digits corresponded to a geographic region of the US until 2011. First the state where the number was issued and later the zip code of the Social Security card applicant.
The second set of two digits were known as the “group” numbers and despite rumors on the internet, they only organized the soon to be millions of files. The “group” numbers were not used consecutively. First, only the odd numbers 01 through 09 were used, followed by the even pairs of 10 through 98. When all numbers in group 98 were used then the even pairs 02 through 08 were used, followed by only the odd numbers 11 through 99.
Each group number is followed by a “serial number” that were used sequentially, starting with “0001”. Once all the serial numbers in a “group” were used up, a new “group” number would be used.
There are other number combinations that are not used, such as issuing Social Security Numbers with “666” for the first three digits. None of the three sections will ever have all “zeros”. And no social security number starts with the number “9”.
Almost half of potential social security numbers still available
The nine-digit combination of numbers, taking into account the unauthorized combinations, the agency lists approximately 900 million unique social security numbers. Each region of the US was assigned a certain number of Social Security Numbers through the “area” number.
However, when the Social Security Administration originally designed its numbering system, parts of the US were sparsely populated. As a result of migrating to those areas, the agency ran into a number crisis and failed to allocate enough numbers for future beneficiaries. So in 2011, the Social Security Administration switched to using “randomization” for issuing new Social Security numbers.
As well as freeing up songs from regions with higher allocations a few more songs were cleared to use. Previously, the number “8” was not allowed to be used as the first of the nine digits. Now that the Social Security Administration has issued about 450 and about a million numbers so the agency has just under half its number still available. Those numbers are expected to cover the next 50 or more years of new applicants before a more fundamental change to the numbering scheme is still needed.