Decoding Social Security Numbers in One Step

Decoding Social Security Numbers in One Step

Stephen P. Morse, San Francisco

Three-Digit Decoder

SSN starting with	- XX - XXXX
was issued in
	Where card was issued, not where person was born

Five-Digit Decoder

SSN starting with	- - XXXX
was issued in	001-01: New Hampshire, 1936-1950"
	Where and when card was issued, not where and when person was born

Three-Digit Assignment Chart

NW* = North Carolina if next two digits are 30, otherwise West Virginia

PI* = Pacific Islands (Guam, American Samoa, Northern Mariana Islands, Philipines)

RR* = Railroad Workers

EE* = Enumeration at Entry

ITIN* = Individual Taxpayer Identification Number if next two digits are in range 70-88

XX* = Unassigned

The structure of Social Security Numbers can be found in Jerry Crow and Barbara Bennett's article .
Later number assignments can be found at the Social Security Administration website
The structure of Individual Taxpayer Identification Numbers can be found on the Internal Revue Service website .
This page is automatically updated monthly

© Stephen P. Morse, 2007