Social Security Number Allocations by Location

Social Security Number Allocations by Location The first three digits of a persons Social Security number numbers can often help you to determine where your ancestor may have possibly been living when his/her SSN was issued (see exceptions below). These numbers can also be helpful in determining which listings in the SSDI may belong to your ancestor. The first three digits of a persons Social Security number were, prior to 1973, determined by the state where the person applied fo their social security card. Since that time, the first three digits have been assigned based on the ZIP Code of the mailing address on the Social Security number application. The chart below shows the first 3 digits of the social security numbers assigned throughout the United States and its possessions. SOCIAL SECURITY NUMBER STATE CODES * The same number, when shown with more than one area, means that certain numbers have been transferred from one State to another, or that an area has been divided for use among certain geographic locations. Learn more about the other numbers in the Social Security Numbering Scheme.