What Do Social Security Numbers Start With? First Three Digits Explained

Social Security Numbers issued today can start with any three-digit combination from 001 through 899, with one exception: 666 is never used. The Social Security Administration switched to random assignment on June 25, 2011, so the opening digits of a newly issued SSN no longer reveal anything about where the holder lives or when the number was assigned. For numbers issued before that date, the first three digits — called the area number — did carry geographic meaning, running low in the Northeast and climbing westward.¹

What the First Three Digits Mean Now

Since June 25, 2011, the area number is random. A baby born in Ohio and a baby born in Oregon can receive SSNs whose first digits look nothing alike, or nearly identical. The middle two digits (the group number) no longer follow the old odd-even filing cycle, and the last four (the serial number) are no longer sequential.¹

The SSA gave two reasons for the change. Random assignment makes an SSN harder to guess from public facts like state and year of birth. It also stretches the remaining supply of numbers, because some state allocations were nearly exhausted while others sat largely unused. Randomization opened previously unassigned blocks — most notably the 800 series — and spread new numbers evenly across the country.²

What the First Three Digits Meant Before 2011

For SSNs issued before June 25, 2011, the area number linked the card to a place. New England drew the lowest numbers and the Pacific states drew the highest. A card issued in New Hampshire might start with 001 to 003; a Californian’s could fall in 545–573 or 602–626.³

The link was looser than it looked. Before 1972, the area number reflected whichever local SSA office processed the application, and you could apply at any office in the country. After 1972, when card issuance moved to Baltimore, the area number was based on the ZIP code of the mailing address on the application, which didn’t have to be the applicant’s actual residence.³

Historical area-number ranges for pre-2011 SSNs:

001–134: New England and New York
135–231: New Jersey, Pennsylvania, Maryland, Delaware, Virginia
232–267: West Virginia, North Carolina, South Carolina, Georgia, Florida
268–399: Ohio, Indiana, Illinois, Michigan, Wisconsin
400–467: Kentucky, Tennessee, Alabama, Mississippi, Arkansas, Louisiana, Oklahoma, Texas
468–515: Minnesota, Iowa, Missouri, North Dakota, South Dakota, Nebraska, Kansas
516–576: Montana, Idaho, Wyoming, Colorado, New Mexico, Arizona, Utah, Nevada, Washington, Oregon, California, Alaska, Hawaii
577–584, 596–599: District of Columbia, Virgin Islands, Puerto Rico

Several states later picked up extra ranges as their original blocks ran thin. Florida added 589–595, Texas added 627–645, and California added 602–626. A separate block, 700–729, was reserved for railroad workers regardless of location and was discontinued in 1964.⁴

First Digits That Never Appear

Some opening digits are permanently off the table, and the 2011 change didn’t touch these rules:

000: never assigned. An SSN beginning with 000 is invalid.
666: never assigned and never will be.
900–999: excluded from SSN assignment entirely.

Two more exclusions live inside the number rather than at the start: the middle two digits are never 00, and the last four are never 0000. If you see either, the number isn’t a valid SSN.²

One block did change status. Before 2011, no SSN started with an 8, and fraud-screening tools flagged 800-series numbers as bogus. Since randomization, an SSN beginning with 8 can be perfectly legitimate as long as it was issued on or after June 25, 2011.¹

SSNs That Start With 9 Are Not SSNs

A nine-digit number in SSN format that begins with a 9 is an Individual Taxpayer Identification Number (ITIN), not a Social Security Number. ITINs are issued to people who need a tax identifier but don’t qualify for an SSN. The 900–999 range is reserved and will not appear as the first three digits of any real SSN.²

The Rest of the Number

Every SSN follows the same nine-digit XXX-XX-XXXX layout. The first three digits are the area number. The middle two are the group number. The last four are the serial number.³

Under the old system, the group number wasn’t geographic, but it wasn’t random either. Within each area number, the SSA issued odd groups 01 through 09 first, then even groups 10 through 98, then even groups 02 through 08, and finally odd groups 11 through 99. This pattern was designed for paper filing efficiency.⁵ The SSA published a “High Group List” showing the most recent group number assigned to each area, and the final edition ran on June 24, 2011, the day before randomization made it obsolete.⁶

Serial numbers ran sequentially from 0001 to 9999 within each area-group pair. Once a group hit 9999, the SSA moved to the next group in the cycle above.³ Since 2011, none of that internal sequencing applies to new numbers.

SSNs Are Never Reused

When a person dies, their SSN retires with them. The SSA does not reassign it. The nine-digit format allows roughly one billion combinations after the exclusions, and as of 2008 the agency had issued more than 450 million. The SSA has said it has “many years’ worth of potential SSNs available for future assignment,” and part of the reason for switching to random assignment was to spread that remaining supply evenly rather than let some state allocations run dry while others sat unused.⁴

1
Social Security Administration. Social Security Number Randomization
2
Social Security Administration. Social Security Number Randomization Frequently Asked Questions
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Social Security Administration. Social Security Numbers
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Social Security Administration. The Story of the Social Security Number
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Social Security Administration. Structure of the Social Security Number (SSN)
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Social Security Administration. High Group List and Other Ways to Determine if an SSN is Valid