How Social Security Numbers Are Assigned

Social Security card for Jane Doe

If you have a Social Security number, you may wonder how those specific numbers were assigned to you. Is there a specific process used to assign numbers, or are the numbers randomly assigned? If you guessed that there is a process, you are correct. Each nine-digit Social Security number is created by combining three parts in order to create a number that is specific to the person to whom is assigned to. Some of it is random, and some of it has to do with the state the person is applying from.

Each Social Security Number is set up with three parts, like this:


The Social Security website explains what each of these three parts means:

  1. Area Number
  • The area number is the first three digits of the Social Security number.
  • Each area number is assigned to a geographical region, however, the Social Security website points out a few important things:
    • Cards were previously issued in Social Security areas around the United States. Currently, each Social Security Number’s area number is assigned by the zip code in the mailing address listed on the Social Security application. This means the area number may not be an accurate representation of the state of residence of the applicant if their zip code spans multiple states.
    • The Social Security website emphasizes that the area number is not meant to be useable geographical information, since its original creation was “really just a bookkeeping device.”
  • The SSA website shows the Social Security Area Number Allocations and the states each number corresponds with.
  1. Group Number
  • The middle two digits range from 01 to 99 but they are not assigned in consecutive order.
  1. Serial Number
  • The Social Security website says the last four digits of each Social Security Number, called Serial Numbers, run consecutively from 0001 to 9999.

There are a few other interesting facts about Social Security Numbers:

  • Any number beginning with a 000 is not and will never be a valid Social Security Number.
  • After June 25, 2011, Social Security Number Randomization was created and the “High Group List”, a list that contained data from 2003 to 2011, was eliminated. Each data set shows what ranges of Social Security numbers have been issued and was designed to help people determine whether or not their Social Security Number was valid. You can still view all the High Group History lists from November 2003 to June 2011.
  • The group number is occasionally rumored to be about racial groupings, when it is not at all. Race is not factored into a person’s Social Security Number at all.

Photo Courtesy of Creative Commons and Donkey Hotey.