# What happens when they run out of SS numbers? **URL:** \ **Category:** Factual Questions\ **Created:** [June 7, 2025, 9:27pm UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311 "2025-06-07T21:27:38Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [June 7, 2025, 9:27pm UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311/1 "2025-06-07T21:27:38Z")
There are only a billion 9 digit numbers. Since there are 350,000,000 Americans nearly all with SSNs and likely another couple hundred million deceased, it is predictable that at some time in this century, they will have run out of numbers. Are there any plans for dealing with this? Canada also uses a 9 digit SIN, but I think we are good for this millennium. One solution that occurs to me is to start using alphabetic codes. For example, replace the 30 (4th and 5th digits which somehow codes for the mid-Atlantic states) by PA on my number. That would solve the problem for a long time. Until there were a billion Californians. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [June 7, 2025, 9:29pm UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311/2 "2025-06-07T21:29:44Z")
As of right now, there are no plans to change anything. [https://www.ssa.gov/history/hfaq.html](https://www.ssa.gov/history/hfaq.html) > **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. Edit, I’m also reading that, in 2011, they started randomizing the numbers to allow more combinations. [https://www.ssa.gov/employer/randomization.html](https://www.ssa.gov/employer/randomization.html) > It eliminated the geographical significance of the first three digits of the SSN, referred to as the area number, by no longer allocating the area numbers for assignment to individuals in specific states. ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [June 7, 2025, 9:36pm UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311/3 "2025-06-07T21:36:04Z")
But are all numbers on the table from 000-00-0000 to 999-99-9999 available? I thought SS numbers had some info embedded into them. Like where they were issued (roughly…like state where it was issued…I had someone notice my SS# was issued in California even though I am from Illinois…it was issued in California). That would suggest they can’t just use all the numbers. But, @Joey_P cite suggests maybe they can (or they are giving us the short version). ETA: It seems @Joey_P answered this in an edit while I was writing and close to a simulpost for that added bit. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [June 7, 2025, 9:39pm UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311/4 "2025-06-07T21:39:26Z")
Yes, some numbers aren’t used, but part of that randomization introduced new numbers that weren’t used previously. > Previously unassigned area numbers were introduced for assignment excluding area numbers 000, 666 and 900-999. If my math is right, and it might not be, excluding those 102 area numbers removes just shy of 102 million possible numbers, but that still leaves 900 million numbers, of which about half have already been used. ---
**Author:** ![hajario](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hajario/32/171_2.png) [@hajario](https://boards.straightdope.com/u/hajario)\ **Post date:** [June 7, 2025, 10:08pm UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311/5 "2025-06-07T22:08:57Z")
This web page decodes the place and year of issue for SSNs prior to the randomization of 2011. As most of us know, prior to the the mid-80s when tax laws changed, people didn’t get them until later in life typically when they were going to start working and paying taxes. I apparently got mine when I was 12. I have a vague memory that that was when I opened a bank account and they offered me a form to get one which makes sense in case at some point they would need to report interest income for me. > **[Decoding Social Security Numbers in One Step](https://stevemorse.org/ssn/ssn.html)** ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [June 8, 2025, 3:07am UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311/6 "2025-06-08T03:07:23Z")
The simplest thing to do would be to add a digit, and make every existing SSN start with zero. ---
**Author:** ![hajario](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hajario/32/171_2.png) [@hajario](https://boards.straightdope.com/u/hajario)\ **Post date:** [June 8, 2025, 3:19am UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311/7 "2025-06-08T03:19:25Z")
I think it would be easier to use letters for the leading digit but we won’t be around when they have to decide. ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [June 8, 2025, 3:54am UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311/8 "2025-06-08T03:54:18Z")
Adding a digit would be hugely disruptive to all the software that deals with social security numbers, in banks, employment records, etc. Changing to alphanumerics would also be disruptive but I think significantly less so. When Medicare stopped using social security numbers a few years ago, they switched to alphanumerics but with the same 9 character format as social security numbers. ---
**Author:** ![penultima\_thule](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/penultima_thule/32/3833_2.png) [@penultima\_thule](https://boards.straightdope.com/u/penultima_thule)\ **Post date:** [June 8, 2025, 4:26am UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311/9 "2025-06-08T04:26:15Z")
> [@puzzlegal](#): > > The simplest thing to do would be to add a digit, and make every existing SSN start with zero On the assumption that SS numbers with the format 999-99-9999 are actually alphanumeric, the simplest thing would be to maintain the 9 digits and format but extend the series with the first character being “A”. Or if you were really sure the Republic would stand that long commence with “AA9-99-9999”. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [June 8, 2025, 7:11am UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311/10 "2025-06-08T07:11:16Z")
I wonder if there are systems out there that store the number as a numeric value rather than a string. Those would be broken by prefixing with zero or alpha. ---
**Author:** ![Bullitt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bullitt/32/5725_2.png) [@Bullitt](https://boards.straightdope.com/u/Bullitt)\ **Post date:** [June 8, 2025, 9:07am UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311/11 "2025-06-08T09:07:19Z")
Many systems store them as numeric. My career was in medical device robotics and software EMRs. Many systems would have to change. But it’s like the major exercises during the Y2K transition where we had to flesh out all the data fields and algorithms that presumed 2 digits for, e.g., birth year. ---
**Author:** ![Bullitt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bullitt/32/5725_2.png) [@Bullitt](https://boards.straightdope.com/u/Bullitt)\ **Post date:** [June 8, 2025, 9:11am UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311/12 "2025-06-08T09:11:41Z")
> [@hajario](#): > > This web page decodes the place and year of issue for SSNs prior to the randomization of 2011. As most of us know, prior to the the mid-80s when tax laws changed, people didn’t get them until later in life typically when they were going to start working and paying taxes. > > I apparently got mine when I was 12. I have a vague memory that that was when I opened a bank account and they offered me a form to get one which makes sense in case at some point they would need to report interest income for me. > > [Decoding Social Security Numbers in One Step](https://stevemorse.org/ssn/ssn.html) This site was cool to play with. My parents and I and 2 of my siblings were all born in the Philippines. We all became citizens in Upstate New York at the same time, in the Albany NY courthouse. All of our SSNs start with the same 5 digits, and this site spit out the year when we became US citizens. Pretty cool. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [June 8, 2025, 11:21am UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311/13 "2025-06-08T11:21:59Z")
Yeah, I can believe it. Having worked in and with software development, people making naive decisions about data types and sizes is all too common. I remember having to try to work on a system that had been written when all ISBNs were 10 digits and that had been baked into every part of the thing and was also being used as a primary key. It was a huge mess. ---
**Author:** ![Mean\_Mr.Mustard](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mean_mr.mustard/32/3865_2.png) [@Mean\_Mr.Mustard](https://boards.straightdope.com/u/Mean_Mr.Mustard)\ **Post date:** [June 8, 2025, 11:35am UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311/14 "2025-06-08T11:35:15Z")
> [@markn\_1](#): > > Adding a digit would be hugely disruptive to all the software… Holy crap, it’ll be Y2K all over again! mmm ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [June 8, 2025, 12:32pm UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311/15 "2025-06-08T12:32:42Z")
Any change will be similar to y2k. Except it will only affect things that depend on SSNs, and we’ve already practiced with the actual y2k. So i think we’ll manage. ---
**Author:** ![hajario](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hajario/32/171_2.png) [@hajario](https://boards.straightdope.com/u/hajario)\ **Post date:** [June 8, 2025, 12:42pm UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311/16 "2025-06-08T12:42:32Z")
Everyone involved with Y2K will be dead by then ---
**Author:** ![slash2k](https://avatars.discourse-cdn.com/v4/letter/s/439d5e/32.png) [@slash2k](https://boards.straightdope.com/u/slash2k)\ **Post date:** [June 8, 2025, 12:44pm UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311/17 "2025-06-08T12:44:07Z")
Social Security numbers can already start with a zero: 001, e.g., was historically used as a prefix for numbers assigned in New Hampshire, and President Obama famously had 042-68-4425 (he got a new one after this was publicly disclosed). ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [June 8, 2025, 12:52pm UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311/18 "2025-06-08T12:52:12Z")
If one starting number was unused, it would be possible to provision unlimited SSNs of varying lengths, for example if only the digits 0-8 were currently in use, 9 could have been reserved to indicate the start of a 10-digit SSN and that’s possible recursively - so 90 to 98 would be 10 digits, 99 indictating 11 digits for the range starting 990 to 998, with 999 being 12 digits and so on. I’ve seen this done with telephone numbers but for US SSNs I imagine that ship has sailed though. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [June 8, 2025, 12:56pm UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311/19 "2025-06-08T12:56:50Z")
> [@Hari\_Seldon](#): > > Canada also uses a 9 digit SIN, but I think we are good for this millennium. We’re good for a while yet, but there are actually only 8 usable digits in the Canadian SIN. The 9th digit is a check digit. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [June 8, 2025, 2:06pm UTC](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311/20 "2025-06-08T14:06:06Z")
Here’s a (very) old thread on point: > [@How long until we run out of Social Security numbers?](https://boards.straightdope.com/t/how-long-until-we-run-out-of-social-security-numbers/427959): > > Google has failed me, as has Cecil’s column archive. I know the Social Security Administration is re-using the numbers of some dead people now, but with longer lifespans I’m thinking that’s probably a stop-gap measure. Will the numbers eventually have to grow longer by a few digits? What’s the Straight Dope? I recall us discussing this topic afresh sometime in the last couple of years. I’m not able to guess the right combo of words to find the title now, nor find my contributions to it. [Next page](https://boards.straightdope.com/t/what-happens-when-they-run-out-of-ss-numbers/1019311.md?page=2)