TN 2 (06-11)

RM 10201.030 Structure of the Social Security Number (SSN)

The SSN consists of nine digits, separated into three groups by hyphens (i.e., 000-00-0000). This section contains a description of what each group of numbers represented in the Social Security Number (SSN), prior to June 25, 2011. Beginning June 25, 2011 forward, this structure is no longer of any significance.

NOTE: Information about the structure of the SSN is not restricted. Field offices (FOs) may respond to inquiries about the significance of the SSN structure and State allocations of area numbers.

A. SSN area number

Prior to June 25, 2011, the first three digits of the SSN represented the area number. The area number reflected the State as derived from the ZIP Code in the mailing address the number holder provided on the application for an original SSN card.

B. SSN group number

Prior to June 25, 2011, the middle two digits of the SSN represented the group number. The group number ranged from 01 to 99. For administrative reasons, we assigned group numbers in the following sequence:

  1. odd numbers from 01 through 09;

  2. even numbers from 10 through 98;

  3. even numbers from 02 through 08; and finally,

  4. odd numbers 11 through 99.

C. SSN serial number

Prior to June 25, 2011, the last four digits of the SSN represented the serial number. The serial number represents a straight numerical series of numbers from 0001-9999 within each group.

D. See also


To Link to this section - Use this URL:
http://policy.ssa.gov/poms.nsf/lnx/0110201030
RM 10201.030 - Structure of the Social Security Number (SSN) - 06/23/2011
Batch run: 06/23/2011
Rev:06/23/2011