SSN Policy Manual

Policy Manual

First Three Digits

State

Not in use

596-599

Arizona

600-601

California

602-626

I

Not in use

627-699

I

I

Railroad Retirement

700-728

I

Not in use

729-999

The following range of first three digits are currently not used by the Social Security Administration:

233 through236 596 through 599 627 through 699 729 through 999