Why SSN Numbers Will Run Out (Explained)

America’s Social Security Number was not originally meant to be a universal identifier of its citizens. However, it has expanded into federal and commercial use for that purpose.

Unfortunately, the SSN system doesn’t meet the requirements of an identification number of a country with a population size of the United States.

This article looks into the reasons why SSN doesn’t work for universal identification.

Early Concerns About SSN

I’ve written a separate in-depth article on the history of SSN in the U.S, which details the expansion of the system.

I’ll briefly say here that the system was introduced in 1936 to support relief systems during the Great Depression.

The linked article will show you how it went from modest goals to being deployed as a universal identifier.

By the early 1940s, mathematicians were pointing out the flaws in the design of a nine-digit number. But that wasn’t the only concern. Let’s get into them in turn.

Why A Nine Digit Number Can’t Work For The U.S. Population

The SSN is a nine-digit number. This may seem long when you’re trying to memorize it, but in mathematical turns – it’s tiny.

There are 999,999,999 possible combinations of nine-digit numbers – you can read that as one shy of a billion.

That may make you sit back and think – well, we are nowhere near a billion people in the United States so there’s nothing to worry about.

But SSNs can’t be simply reused after the death of an individual. As widows’ pensions and other family benefits depend on the number, they must be kept intact for many years.

Running out of numbers

There are currently about 327 million people in the United States, so that’s a third of the combinations gone. Then think of all the people who had one and died since 1936.

How many is that? Well, the Social Security Board is keeping tight-lipped about this (they do know!). All they say officially is:

“The nine-digit SSN will eventually be exhausted.”

Social Security Board FAQ

Don’t think that this is like astronomers saying that a giant comet will eventually hit the earth – in a thousand million years from now.

The “eventually” for nine-digit numbers is possibly in your lifetime. It’s certainly before the end of the 21st century.

How The SSN Digit Design Made Things Worse

The previous section assumed that an SSN was made up of any possible combination of nine digits. But the design of SSN didn’t use a random assignment of numbers.

Instead, different sections have different meanings and there are combinations of numbers that aren’t allowed.

The first section has historically been based on geography. Although the rules have changed over the years, the first three digits have specified the actual state of the individual.

In more recent years, these numbers were based on the zip code on the application form. But again it ties the digits down in non-random ways.

The two middle digits (digit #4 and #5), are also specific to various regions. Other rules determine whether odd or even numbers are used for specific individuals.

The third section of four digits can range from 0001 to 9999. Even if this section is genuinely random, this greatly reduces the potential combinations when compared to a nine-digit number

Current design to fix this non-random problem

In 2011, the Social Security Board changed the design to alleviate this issue of non-randomized numbers.

They removed the ties of the first three digits to geography and switched to a random allocation.

They also introduced a random element to the middle two digits (known as the group numbers).

Problem not completely solved!

These 2011 changes certainly alleviated the immediate problems of running out of numbers within a few decades.

The Social Security Board has extended the lifetime of issuing unique SSN for another forty or fifty years.

SSN Allocation Is Not Universal

Many western countries assign a unique identity number to every registered birth. No ifs, ands, or buts! Every citizen gets a number.

In these countries, immigrants must secure an identification number before getting work or benefits. This means that only undocumented inhabitants can avoid an identity number.

Historically, the U.S. has been very different. You can read about the history of SSN in our separate article.

I’ll point out here that the U.S. system involves adults applying for an SSN when they needed one.

For decades, people didn’t need one to get married, to get a driving license, or to get some types of benefits. This means that many older people don’t have an SSN.

The need for an SSN greatly expanded over the decades, which means that most younger adults will have one. But it’s still possible to go through life without one.

No In-Built Quality Check

Lengthy identification numbers like the SSN are very easy to misremember or mistype.

Because of this, many ID systems include a check digit. This digit is purely to check that the other numbers are correct (and in the correct order).

You can think of it as representing something like “digit #1 plus digit #2 minus digit#3…” and so on.

This means that computer systems can recognize and reject invalid numbers immediately. This is a great help in preventing wrong entries (although it also can help fraudsters).

You may not be surprised that the SSN system devised in 1936 doesn’t have a check digit.

Can You Get A New More Randomized SSN?

The general federal policy is that people can’t get a new SSN if they already have been issued one in the past. After all, it’s supposed to track you from cradle to grave.

However, they make exceptions where the non-randomized element has caused problems for individuals. You have to make your case!

Relatives with sequential numbers

One of the more common problems is when siblings discover that they have sequential numbers. Why is this a problem? Well, it’s a great advantage for identity-theft scammers.

When they get hold of one SSN, they can “test” a similar number with similar names. This can cause a hit where legitimate SSNs have been issued to siblings.

This is most likely to happen when parents have sent in applications at the same time for two young children.

You have already been hit by identity theft

Are you in a situation where you’ve reported your case of identity theft to your bank and law enforcement?

Once you have the official paperwork, you can engage with the Social Security Board to request a new SSN.

You learn that you have a non-unique SSN

In this scenario, people accidentally learn that they have the same SSN as another individual.

But it’s not a case of identity theft! It’s because the issuing of numbers hasn’t been random for most of the existence of the system.

People tend to find this out when an official of some kind points this out. You may be applying for a driving license, and the agency informs you that there’s a problem with your SSN.

In these cases, you should have little trouble with getting a new one from the Social Security Board. They have the evidence in their databases!