Historical SSN Reference

Social Security Number Prefixes by State

The Social Security number (SSN) is a nine-digit number issued to U.S. citizens, permanent residents, and temporary working residents. The number is divided into three parts: the area number (first three digits), the group number (middle two digits), and the serial number (last four digits). The area number, or prefix, was historically tied to the Social Security office or mailing address used when the number was issued.

For Social Security Numbers issued prior to 2011, you may use the search box below to determine the historical Social Security office area or mailing-address state associated with the applicant.

Prefix Lookup

Search historical SSN area numbers

Prefix	State Code	State Name
121	NY	New York
122	NY	New York
123	NY	New York
124	NY	New York
125	NY	New York
126	NY	New York
127	NY	New York
128	NY	New York
129	NY	New York
130	NY	New York
131	NY	New York
132	NY	New York
133	NY	New York
134	NY	New York
135	NJ	New Jersey
135	NJ	New Jersey
136	NJ	New Jersey
136	NJ	New Jersey
137	NJ	New Jersey
137	NJ	New Jersey

Social Security Number Breakdown

The Social Security number (SSN) is broken down into the area number (first 3 digits), the group number (the middle two digits), and the serial number (the last four digits).

1. Area Number (Prefix)

The first three digits of the SSN are known as the area number. Historically, this number was tied to the geographical region where the SSN was issued.
Prior to 1972, the area number was based on the location of the Social Security office that issued the number.
From 1972 to 2011, the area number reflected the ZIP code of the mailing address on the SSN application.
Since 2011, the Social Security Administration (SSA) has used a randomized method to assign SSNs, making the area number no longer indicative of the state of issuance.

Assigning a Social Security Number

Initial Issuance

At birth: Most people in the U.S. receive their SSN at birth. Hospitals typically provide parents with a birth registration form, which includes an option to apply for the child's SSN.
Application process: If the SSN is not assigned at birth, parents or guardians can apply for a number at a later date through the SSA.

Application Requirements

U.S. citizens must provide proof of identity, age, and U.S. citizenship, such as a birth certificate or passport.
Non-citizens must provide documents proving immigration status, work eligibility, and identity, such as a visa or work permit.

Assignment and Issuance

The SSA verifies the provided documents.
An SSN is then assigned, and the Social Security card is mailed to the applicant.
The SSN is unique and remains with the individual for their entire life.

Changes Over Time

In 2011, the SSA implemented randomization to help protect the integrity of the SSN and extend its longevity. This means that area numbers no longer reflect geographical regions, making it more difficult to determine where an SSN was issued based solely on its prefix.

Summary

The first three digits of the SSN were once tied to the state of issuance but have been randomized since 2011.

SSNs are typically assigned at birth but can be applied for later.
The assignment involves verification of identity, age, and citizenship or immigration status.
SSNs are unique and lifelong identifiers.

This table should be used as a historical reference only. A modern SSN prefix does not reliably identify a person's state, address, citizenship status, or current residence.