What happens when the US runs out of SSNs?

Just add another digit and watch the entire country break down because they can't find someone to update their 40+ year old software written in COBOL.

Sorry we can't employ you as your ssn is too long. Also we can't have any new employees called Mike Smith as the HR system already has someone with that name.
- The LMS we use at my school can't handle multiple students with the same name. So we have John Smith and John Smith-2. We have like 2000 new students each year, and we have recently transitioned to this LMS. Smh
- Try XxMikeSmithxX
- And 69420 Mike Hunt's
I want to see the high-octane action thriller where the grizzled old hand and the renegade upstart trek to the remote compound in the woods of Montana to find Bob, the last man alive who understands how some obscure part of the IRSs core systems works and bring him back in from the cold for one last job... to save America(s neglected computer systems from decades of under investment)
- Act II needs to have an overdone political scene where congress doesn’t want to pass the budget and almost shuts down the Fed meanwhile some hackers from <focus group hated country> try to take advantage of the situation or whatever
AI, Sure! Here's the full code:

.....

We could switch to hexadecimal digits and we’d be good for 68 billion.

Why stop at hex? You could use the entire alphabet. Even if you take only uppercase letters and numbers, we are at 36^9 possible numbers. If we include lowercase and special characters from ASCII, we can go much further.
- E. G. For storage and performs reasons. 5 bytes vs 9 bytes. Multiplying by amount of users and various indexes - can produce very noticeably difference. More records per page.
- It's all fun and games until you're assigned an SSN that contains a profanity. Because you know there's a strong chance they'll forget to implement a check for that until someone complains, and an even stronger chance that something that looks like a profanity will escape the first implementation of checks.
  
  e.g. There will be someone assigned IMABUM123 and a) that will get through the understaffed / automated profanity check (no four letter words) and b) the person who gets it will have so many problems getting people to believe that it's really their SSN, including the people who could assign them a new one.
Just use IPv6

Social Security numbers are not unique identifiers.

Really?
- Nope.
  
  If you got your social Security number before 2011, your first three digits represent the geographical location you were born in. You share those three digits with each of your siblings who were born in the same geographical location before in 2011. Go ahead and ask them.
  
  If memory serves, and all we would really need to do is check a Wikipedia article, the middle two digits were done in some weird sequence, and then the last four were pseudo-random.
  
  So basically, any people receiving their social security number any multiple of 100 people apart from another (prior to 2011) in the same geographic location have a 1 in 10,000 chance of having identical social security numbers.
  
  Basically, if you live in a large city, you definitely have a few twinsies out there.
  
  This was changed in 2011, because of this, but it is still not a unique identifier. It's just more random.
Thank you!

SS numbers can't start with a 9, so you might wanna recalculate that.

Why not?
- Reserved for employer identification numbers.
- I think they're used as placeholders while they file the documents. My OG SS number started with 950, but that only lasted until the paperwork was complete.
  
  Obviously I won't be sharing my private info here though, but yeah, those numbers can't officially start with a 9.

Considering there are around 330M citizens right now, I think they ran out already and they’re probably recycling them.

The first SSNs were issued in 1936 https://en.wikipedia.org/wiki/Social_Security_number

According to the death master file entry in wiki 111x10^6 SSNs died between 1962 and 2018. https://en.wikipedia.org/wiki/Death_Master_File

That's 1.982 x 10^6 x deaths x year^-1. Assume that number to be a constant during the period 1936-2024

1.982 x 10^6 x deaths x year^-1 x (2024-1936) x year = 174.4 x 10^6 deaths

According to https://en.wikipedia.org/wiki/Demographics_of_the_United_States there's 335.9 x 10^6 residents, but I can't tell if they are citizens with SSNs, but I'm going to assume that for now.

So (335.9 + 174.4) x 10^6 is 510.3 x 10^6 spent SSNs.

According to the same demographics wiki article the birth rate is 11 births per 1000 population. Death rate is 10.4 deaths per 1000 population. Because I'm just doing back of the envelope estimation for fun, while trying to manage my hangover in the early afternoon, I'm not going to create an exponential function to describe population growth. Instead I'm going to only consider future the US population a constant and not consider the 200 x 10^3 annual net growth (it only affects the next year's growth by 120 anyway)

With all of that BS out of the way, at the present birthrate the US requires 3.695 x 10^6 new SSNs annually. The total amount SSNs in the current scheme is (10^9) - 1. I'm going to be leaving out the -1. 10^9 total SSNs - 510.3x^6 spent SSNs leaves 489.7 x 10^6 SSNs available. 489.7/3.695 is 132.5.

So in conclusion, assuming a constant population, the US can go for another 132.5 years with the present scheme without having to reuse any SSN.
- SSN’s are also given out to immigrants as well though, so that’s a whole other population of people outside of just natural born citizens to account for. The US awards around one million green cards annually, though I don’t know what the historical numbers are.
- How about dead SSNs between ‘36 and ‘62? Great work on the calculation but all I’m saying is, if the government ran out of numbers and recycled them already, nobody would know about it. The whole situation is ridiculous if you ask me and there’s no database of SSNs you can compare it to. Weirdly enough, official government departments straight up lie about things and easily get away with it heh.
You could be right about them recycling numbers already, but 330 million < 999 million, so that wouldn't be why
- They say they're not recycling them.
- Oh, I didn't realize that we were in the presence of a connoisseur in the ways of mathematics. /s
- Well, if only one generation passed away, that already puts us at 660M lol. Then there’s immigration, temporary issued SSNs based on work visas (huge numbers here btw) and so on.

The birth of the buffer overflow will mark the beginning of the apocalypse. Hold onto your gas, guns, and milk.

I wish I was an overflow baby :-(

Norawy is facing a similar issue. Even though the national identification number is 11 digits, the first 6 are reserved for birth date. The 7th digit has some set of rules derived from which century the birth was (something like 5-9 is reserved for year 2000 and beyond). The 9th digit is even for women and odd for men. The 10th and 11th digit are fixed and derived from the rest of the numbers.

In conclusion, the system only leaves room for around 240 people per date of birth per gender (yes this system assumes 2 genders). So if the birth rate would have a spike, even just for a day, the system could be in trouble.

Could embiggen it by a factor of 10 by removing the gender marker.
- It'd be easier for the government to start assigning new genders
- Since the distribution of male/female is roughly 1:1, that wouldn't really do anything (except for positively being more accepting). The real solution would be to unlock one of the two last digits, but you can bet that a ton of systems will break as they validate those digits.

Office Space 2

"When the Overflow was noticed, everyone started updating their systems. And this causes people to fall through the cracks. Usually those people are just written off, but what we do is we take those people for ourselves."

"So you're stealing people?"

"No we're not stealing people. They don't have SSNs so they aren't technically people?"

Maybe they can just add one digit, or start using A-F

Probably recycle the oldest ones because those people will be long dead by then.

But let's not kid ourselves, everyone paying into SS right now is never going to get the benefit of it because it will have collapsed.

It can never collapse unless Congress votes to make it collapse. Even in the future once the trust fund is spent down, benefits will be reduced to what comes in from current workers. That's not the full amount but it will be something. I think something like 70%.

So it's not going to collapse unless you think that anything but full benefits is a collapse.

I don't know how you could possibly fit 999,999,999 people into an SSN, or even the entire current fleet of US SSNs. And I don't know how reusing numbers will help, given the time to build a new SSN. But it will undoubtedly be a disaster for the USN and the US. Hopefully, some of us outside the US, will be alive to make memes about it.

Does it even have that many permutations when the first 3 and middle 2 are coded to actually mean something?

Permanently Deleted

They are regularly recycled.

Not according to the SSA’s Q&A:

Q20: Are Social Security numbers reused after a person dies?

A: No. We do not reassign a Social Security number (SSN) after the number holder's death. Even though we have issued over 453 million SSNs so far, and we assign about 5 and one-half million new numbers a year, the current numbering system will provide us with enough new numbers for several generations into the future with no changes in the numbering system.
- Haha, your reply beat out mine by only a minute.
This does not agree with what the Social Security Administration has published:

Q20: Are Social Security numbers reused after a person dies?

A: No. We do not reassign a Social Security number (SSN) after the number holder's death. Even though we have issued over 453 million SSNs so far, and we assign about 5 and one-half million new numbers a year, the current numbering system will provide us with enough new numbers for several generations into the future with no changes in the numbering system.
The maximum possible combinations given the current rules set forth by the SSA is 888,931,098.
The United States population on October 11, 2024 is: 337,248,197 The estimated population of humans on earth is 8,078,345,740

The social security administration has said they have enough SSNs to last for about the next 70 years, and will address this issue in the future.
- Shouldn't they do it while the COBOL people are alive to fix the code?
- But people have been born and died, no? I’m sure total used is closer to something like 500-600 million?
The possible combinations exceed the maximum occupancy of this planet.

Only one country gets SSNs, not the whole planet.
- Don't remind then that America isn't the world.
  
  Also, ~999M is a whole lot less than the ~8B population we have now, so that is veritably not true
- Yes, thats pretty well known and nobody is saying otherwise. It is a comparison of amounts. Say we have 100 billion SSN combinations (I made that number up). Let's also say the maximum occupancy of the planet (OP's words) is 50 billion. That means the amount of numbers, or possible combinations in OP's words, 100 billion, is greater than the maximum occupancy, 50 billion. That's it. Nothing in that says everyone on the planet gets one. It's only comparing the amount of SSNs vs the number of people on the planet.