About Social Security Numbers

Since 1972, social security numbers have been issued by the central office of the  Social Security Administration. The first three (3) digits of a person's social security number are determined by the ZIP Code of the mailing address shown on the application for a social security number. Prior to 1972, social security numbers were assigned by field offices.  The number merely established that his/her card was issued by one of our offices in that State.

Social Security Number - Area Group Serial

The Social Security number consists of nine (9) digits - 1 2 3 - 4 5 - 6 7 8 9. The first three digits of a social security number denote the area (or State) where the application for an original Social Security number was filed.

Within each area, the group number (middle two (2) digits) range from 01 to 99 but are not assigned in consecutive order. For administrative reasons, group numbers issued first consist of the ODD numbers from 01 through 09 and then EVEN numbers from 10 through 98, within each area number allocated to a State. After all numbers in group 98 of a particular area have been issued, the EVEN Groups 02 through 08 are used, followed by ODD Groups 11 through 99.

Within each group, the serial numbers (last four (4) digits) run consecutively from 0001 through 9999.

This chart below shows how Group numbers are assigned:
ODD - 01, 03, 05, 07, 09------EVEN - 10 to 98
EVEN - 02, 04, 06, 08------ODD - 11 to 99
 

• Death Index Database (SSN) - Online searchable database of deaths within the U.S. by name or Social Security Number (SSN).

• Social Security Administration Homepage - Provides employers with information on the administration of social security.

• Social Security Number Validator