How Social Security Numbers Work

By: Patrick J. Kiger  | 
Social Security
A Social Security number is important because you need it to get a job, collect Social Security benefits and avail yourself of some other important government services. Douglas Sacha/Getty Images

In the United States, the nine digits that make up your Social Security number (SSN) may be the most important numbers in your life. You are required to apply for your SSN when you start your first job, and it stays with you from then on! We use our SSNs daily, although many times we don't even know it.

Important as it is, we may not know much about the origin of our specific number and how SSNs generally came to be. We certainly do know we don't want other people using our SSN as their own, especially not 40,000 other people, as happened to one woman we'll discuss a little later.


In this article, we'll tell you about how the Social Security program began and answer some common questions regarding SSNs, the Social Security Administration, and your local Social Security office. We'll also tell you what to do if your card is lost or stolen and how you can deal with and prevent Social Security fraud. But first, we'll tell you what your numbers are for, what they mean and how you get the specific number you'll have for the rest of your life.