Social Security Number Codes by State: Table and Railroad Prefixes

If your Social Security Number was issued before June 25, 2011, its first three digits identify the state or territory where you applied for the card. These three digits are called the Area Number, and the Social Security Administration assigned them in geographic blocks starting in the Northeast and working west. Social Security Number codes by state only apply to numbers issued before that 2011 cutoff. Numbers issued afterward are fully randomized and reveal nothing about location.1Social Security Administration. Social Security Number Randomization

Area Number Table by State and Territory

Find the first three digits of the SSN in the ranges below to see which state or territory processed the original application.

  • New Hampshire: 001–003
  • Maine: 004–007
  • Vermont: 008–009
  • Massachusetts: 010–034
  • Rhode Island: 035–039
  • Connecticut: 040–049
  • New York: 050–134
  • New Jersey: 135–158
  • Pennsylvania: 159–211
  • Maryland: 212–220
  • Delaware: 221–222
  • Virginia: 223–231
  • West Virginia: 232–236
  • North Carolina: 237–246
  • South Carolina: 247–251
  • Georgia: 252–260
  • Florida: 261–267, 589–595
  • Ohio: 268–302
  • Indiana: 303–317
  • Illinois: 318–361
  • Michigan: 362–386
  • Wisconsin: 387–399
  • Kentucky: 400–407
  • Tennessee: 408–415
  • Alabama: 416–424
  • Mississippi: 425–428, 587–588
  • Arkansas: 429–432
  • Louisiana: 433–439
  • Oklahoma: 440–448
  • Texas: 449–467
  • Minnesota: 468–477
  • Iowa: 478–485
  • Missouri: 486–500
  • North Dakota: 501–502
  • South Dakota: 503–504
  • Nebraska: 505–508
  • Kansas: 509–515
  • Montana: 516–517
  • Idaho: 518–519
  • Wyoming: 520
  • Colorado: 521–524
  • New Mexico: 525, 585
  • Arizona: 526–527, 600–601
  • Utah: 528–529
  • Nevada: 530
  • Washington: 531–539
  • Oregon: 540–544
  • California: 545–573, 602–626
  • Alaska: 574
  • Hawaii: 575–576
  • District of Columbia: 577–579
  • Virgin Islands: 580
  • Puerto Rico: 580–584, 596–599
  • Guam: 586
  • American Samoa: 586
  • Railroad Retirement Board: 700–728
2Social Security Administration. Social Security Bulletin – Meaning of the Social Security Number

A Few Overlaps and Second Blocks

Several high-population states, including California, Florida, and Arizona, received additional code ranges once their original blocks ran out. Guam and American Samoa share area number 586 and are distinguished by the group number in the middle two digits. The Virgin Islands and Puerto Rico both use 580, again separated by group number.2Social Security Administration. Social Security Bulletin – Meaning of the Social Security Number

Numbers Starting With 700–728: Railroad Workers

Numbers in the 700–728 range weren’t tied to any state. They were issued by the U.S. Railroad Retirement Board to workers with railroad employment after 1936, under a separate registration system that ran until January 1, 1981.3U.S. Railroad Retirement Board. Privacy Act of 1974 System of Records Notice RRB-12 Railroad Employees Registration File If you’re doing genealogical research and find a number that starts with 700–728, it points to rail industry employment during that period rather than to a location.

What the Code Actually Tells You

The Area Number reflects where the person applied for the card, not where they were born. Someone born in Ohio who moved to Florida and applied there would carry a Florida code.2Social Security Administration. Social Security Bulletin – Meaning of the Social Security Number

How that place got determined changed over time. Before 1972, the code came from whichever local SSA field office processed the paperwork. Starting in 1972, the SSA centralized assignment in Baltimore and began using the ZIP code on the application, which still mapped to a state-based block.4Social Security Administration. The Story of the Social Security Number

For most people alive today whose numbers were assigned before 2011, the card came through the Enumeration at Birth program. The hospital collects the information at birth registration and forwards it through the state vital records agency to the SSA. For numbers issued this way before 2011, the code reflects the state where the child was born, because that’s where the birth was registered.5Social Security Administration. POMS RM 10205.505 – Enumeration at Birth Process

The SSA itself has cautioned against reading too much into these codes. They were a bookkeeping tool designed in 1936 so clerks in Baltimore could physically file application cards by region, not a public location database.6Social Security Administration. Social Security Numbers In fraud investigation, a mismatch between someone’s claimed biography and their area code isn’t proof of anything on its own. It’s a pattern, not a certainty.

Why Post-2011 Numbers Don’t Follow the Table

On June 25, 2011, the SSA stopped assigning Area Numbers by geography and switched to full randomization. If a number was issued after that date, the first three digits reveal nothing about where the person lives or applied.1Social Security Administration. Social Security Number Randomization

The SSA gave two reasons. Some state blocks were close to exhaustion while others sat mostly unused, and randomization freed approximately 420 million additional combinations by allowing any valid Area Number to be assigned anywhere. The geographic system had also become a security weakness, because knowing a person’s birth state and approximate birth date narrowed the SSN enough to make prediction feasible.1Social Security Administration. Social Security Number Randomization

Number Patterns That Are Never Valid

Some combinations have never been issued and never will be. If you find one of these on a document, it’s not a real SSN:

  • Area number 000
  • Area number 666
  • Area numbers 900–999 (this range is used for IRS-issued Individual Taxpayer Identification Numbers, or ITINs, for people who need a tax ID but aren’t eligible for an SSN)7Internal Revenue Service. Taxpayer Identification Numbers (TIN)
  • Group number 00 (the middle two digits)
  • Serial number 0000 (the last four digits)

These exclusions applied before randomization and remain in force under the current system.8Social Security Administration. Social Security is Changing the Way SSNs are Issued

Verifying a Number Today

Before 2011, employers could check the SSA’s High Group List to see which group numbers within each Area Number had actually been issued. Randomization ended the usefulness of that list, and the SSA published a final version as a historical archive.9Social Security Administration. High Group List and Other Ways to Determine if an SSN is Valid Employers verifying SSNs now use the SSA’s Social Security Number Verification Service.