SSA publishes a list every month of the highest group assigned for each SSN Area.
For example, if the highest group assigned for area 999 is 72, then we know that the number 9 is an invalid number because even Groups under 9 have not yet been assigned.
The central, two-digit field is called the "group number".
The final, four-digit field is called the "serial number".
First issued in November 1936, to date, over 420 million different Social Security numbers have been issued in the United States.
Since all of your financial records, education, driver’s licenses, insurance and health care are tied to your Social Security number; it is a major factor in identity theft.
As a result, it eventually found its way to Grace D. That’s because cards have not been issued where the first three digits are 000, 666, or higher than 772. Unfortunately, that number belonged to Hilda Schrader Whitcher, the secretary of an E. Ferree company vice president who decided to use her official number on the sample cards. Whitcher’s Social Security number as their own at one time or another. They wanted to know why so many people had her number. If you object to certain digits in your Social Security number you can appeal for a new one, but only if you can prove your concerns are firmly rooted in your religious beliefs or cultural traditions. Social Security numbers are not reused after the card holder dies. Even though numbers aren’t reused, the Social Security Administration says the current numbering system is capable of providing enough new numbers for “several generations into the future.” That means Social Security numbers will still be available well past 2030.
Valid cards are also never issued with the middle two digits or the final four digits all zeros. In 1938 a sample Social Security card with the number 0 was inserted into new wallets manufactured by the E.
The group number is not related to geography but rather to the order in which SSNs are issued for a particular area.
Before 1965, only half the group numbers were used: odd numbers were used below 10 and even numbers were used above 9.