Where Did Social Security Numbers Come From?

Social Security numbers: Most people in the U.S. have them, considering you need them for so many things. Kids need them so their parents can claim them as dependents for tax reasons, you need one to apply for a job, and they’re necessary for collecting many government benefits. If you’ve applied for a credit card or loan, you’ve entered it on your application. Because it’s tied to some of the most important, sensitive data about you, a Social Security number itself is incredibly delicate information, which is why you need to be cautious about whom you give it to.

But what’s so special about a sequence of nine numbers, and how secure can that numbering system be? Should a Social Security number be longer to prevent identity theft? There are lots of questions that surround this string of numbers that is so deeply embedded in Americans’ lives, and to answer them, it helps to know the basics.

Why Nine?

The Social Security numbering scheme was created in 1936 as a way to organize Social Security applications.

“It was really just a bookkeeping device for our own internal use and was never intended to be anything more than that,” says the history section of the Social Security Administration website.

The number is broken into three segments as a part of that filing system: The first three are the area number, the next two are the group number and the last four make up a serial number. It’s almost funny that such an important number started out as something as boring as a way to file paperwork.

Breaking Down the Numbers

Cards used to be issued from offices across the country, and the area number corresponded to the state where the card was issued. The card wasn’t necessarily issued from the applicant’s state of birth or residence, and the same is true now. Since 1972, all cards have been issued from the Social Security Administration office in Baltimore, and the area number is tied to the ZIP code of the mailing address on the application.

So there are your first three. On the group number: Each area has its own set of group numbers, from 01 to 99. There’s a system to the way these are assigned, but they’re not given out consecutively. The serial numbers — the last four digits — run consecutively within each group from 0001 through 9999.

And to finish on a fun fact: More than 453 million Social Security numbers have been issued, and about 5.5 million new numbers are issued each year, according to the administration’s website.

Because the number is unique, it’s kind of like a key to your life. That’s why you should never give it out unless it is absolutely necessary, and you keep your card in a safe place. Don’t leave forms with your number on them lying around, and shred anything containing it that you no longer need.

If you are afraid your Social Security number has been compromised, you should monitor your credit. You can do this for free using the Credit Report Card, which updates two of your credit scores every month for free. Any major, unexpected shift in your credit scores could signal identity theft, and you should pull your free annual credit reports.