SSN Numbers Explained

A Social Security Number or SSN is the most important number assigned to a person living in the United States who is legally allowed to work. This number is required in order to open a bank account, obtain a credit card, get driver's license, buy a car, get domestic health insurance (as opposed to travel insurance), and open a retirement account. The SSN is also needed for employment purposes and for filing tax returns. If you are eligible to apply for one, you should do so as soon as possible.

SSNs are not assigned consecutively; the first was not the lowest number, and the most recent is not the highest. They are assigned regionally and in batches.

The nine-digit SSN, which has been issued in more than 400 million different sequences. Each nine-digit Social Security number is divided into three parts separated by two dashes. For example,123-45-6789. The first part is Area numbers, Second part is Group numbers and the third part is Serial numbers.

Area numbers:-
The first three numbers originally represented the state in which a person first applied for a Social Security card. Numbers started in the northeast and moved westward. This meant that people on the east coast had the lowest numbers and those on the west coast had the highest. Since 1972, the SSA has assigned numbers and issued cards based on the ZIP code in the mailing address provided on the original application form. Since the applicant's mailing address doesn't have to be the same as his residence, his area number doesn't necessarily represent the state in which he resides. For many of us who received our SSNs as infants, the area number indicates the state we were born in. You can find out which area numbers go with each state at SSA.gov: Social Security Number Allocations.

Group numbers:-
These two middle digits, which range from 01 through 99, are simply used to break all the SSNs with the same area number into smaller blocks, which makes administration easier. (The SSA says that, for administrative reasons, group numbers issued first consist of the odd numbers from 01 through 09, and then even numbers from 10 through 98, within each area number assigned to a state. After all the numbers in group 98 of a specific area have been issued, the even groups 02 through 08 are used, followed by odd groups 11 through 99.)

Serial numbers:-
The last four digits of the SSN are the serial number and represent a straight numerical series of numbers from 0001-9999 within each group.

Although SSNs are issued in some order, there is no simple way to tell a person's age based on his Social Security number.

SSN's are not reassigned when a person dies. Benefits may be payable to dependents and survivors of a SSN holder long after they die, and the number is used to administer the payments of benefits.The current nine-digit number system accounts for almost one billion SSNs. Between 1936 and 1993 roughly three-hundred and nintey-two million SSNs were been issued, leaving almost two-thirds of the remaining number combinations available for assignment. More than five million new numbers are assigned each year. Since the 1993 fiscal year, over sixteen million Social Security cards were issued. Of this number, approximately six million were original cards and ten million were replacements.

Is the SSN you have valid?
There are two ways to find out. You can use an online service like SSN Validator, or if you’re concerned about privacy, do it manually by checking out this particular Wikipedia section.