Social Security Numbers began in 1936 as part of the new Social Security program

The first Social Security Number was issued on November 24, 1936, to a woman named Jean Hargrave in Lakewood, New Hampshire. The Social Security Administration (SSA) created the nine-digit number system to track earnings and contributions under the newly established Social Security program, which President Franklin D. Roosevelt signed into law in August 1935. Before this, there was no federal system to record how much workers earned or how much they had paid into a national retirement fund.

The program rolled out gradually. By the end of 1936, about 30 million Social Security Numbers had been issued to workers across the country. The SSA set up field offices and worked with employers to register workers and assign them numbers. Early cards were printed on cardstock and looked quite different from the laminated cards issued today — they were not laminated and were easier to damage, which led to frequent replacements.

The original purpose was narrow: to identify workers for the Social Security retirement and disability insurance system. The number was meant to be used only for that purpose. Over the decades, however, the Social Security Number became a de facto national identifier used by banks, employers, the Internal Revenue Service, and many other organizations — a role it was never designed to fill.

Key Takeaways

  • The first Social Security Number was issued on November 24, 1936, as part of the new Social Security program created by the Social Security Act of 1935.
  • By the end of 1936, about 30 million numbers had been issued to workers, and the SSA continued issuing them through field offices and employer partnerships.
  • Social Security Numbers were originally created only to track earnings and contributions for retirement and disability benefits, not as a general identification number.
  • The nine-digit format has remained the same since 1936, though the way numbers are assigned and the rules about who receives one have changed significantly.

How the SSA assigned the first numbers

The SSA did not have a centralized database in 1936. Instead, field offices across the country issued numbers to workers who came in to register. Employers also played a role — they helped workers understand the program and directed them to local SSA offices. The process was manual and paper-based, with clerks recording information by hand and assigning numbers based on the worker's location and the order in which they registered.

The first three digits of a Social Security Number originally indicated the state where the number was issued. A number starting with 001 to 003 came from New Hampshire, 004 to 007 from Maine, and so on. This geographic coding made it easier for the SSA to track which field office had issued each number. The middle two digits and the final four digits were assigned sequentially as workers registered, though the exact logic behind the sequence was not made public.

In 2011, the SSA stopped using geographic coding for new numbers. The agency began randomizing all nine digits to reduce identity theft and fraud, since criminals could predict or forge numbers based on the old system. Workers who received numbers before 2011 still have numbers that reflect their state of issue, but new numbers issued today do not follow that pattern.

Who received Social Security Numbers in the early years

Initially, Social Security Numbers were issued only to workers covered by the Social Security program. This meant employed people and self-employed people who paid into the system. Children, retirees who were not working, and people who did not work for wages were not issued numbers unless they later became employed.

The rules changed over time. In 1961, the SSA began issuing numbers to children whose parents claimed them as dependents on tax returns, because the Internal Revenue Service needed a way to track dependents. By the 1970s, the SSA was issuing numbers to nearly everyone, including infants and people who had never worked. Today, the SSA issues a number to any U.S. citizen or permanent resident who requests one, and many people receive their first number as infants.

Non-citizens with work authorization can also receive Social Security Numbers. The rules for who qualifies have expanded far beyond the original intent of tracking workers in the Social Security program.

Why the nine-digit format was chosen

The SSA selected a nine-digit format because it could generate enough unique combinations to cover the entire U.S. workforce for decades. A nine-digit number can represent up to one billion different combinations, which seemed more than sufficient in 1936 when the U.S. population was about 127 million. The format was also straightforward to print on cards and straightforward for employers and workers to remember and write down.

The nine digits were divided into three parts: the Area Number (first three digits), the Group Number (middle two digits), and the Serial Number (last four digits). This structure helped the SSA organize and track numbers internally, though the meaning of each part has changed since randomization began in 2011.

How Social Security Numbers became a national identifier

What started as a tool for one federal program gradually became the primary identifier used across American financial and government systems. Banks began asking for Social Security Numbers to open accounts in the 1960s. The Internal Revenue Service required them on tax returns. States used them to issue driver's licenses. Employers used them to report wages. Schools used them to track students.

This expansion happened without a formal decision or law requiring it. Organizations straightforward found the Social Security Number useful because it was already widely known and unique to each person. By the 1980s and 1990s, the Social Security Number had become so embedded in American life that many people thought it was designed as a national ID number from the start.

The SSA has never endorsed this use. The agency has repeatedly stated that the Social Security Number was created for Social Security purposes only. However, the agency has limited power to stop other organizations from using it. Congress has passed some laws restricting how Social Security Numbers can be used — for example, states can no longer print them on driver's licenses — but the number remains the most widely used identifier in the United States.

Changes to Social Security Number assignment since 1936

The most significant change came in 2011, when the SSA stopped assigning numbers based on geography and began randomizing all nine digits. This change was made to reduce identity theft and fraud. Under the old system, criminals could predict valid Social Security Numbers by knowing a person's state and approximate age. Randomization made it much harder to guess or forge numbers.

The SSA also changed the order in which numbers are issued. Previously, the Group Number (middle two digits) followed a specific sequence. Now all digits are assigned randomly, with no pattern that can be predicted or exploited.

Another change involves who receives numbers and when. The SSA now issues numbers to newborns whose parents request them, and to non-citizens with work authorization. The agency also allows people to request a new number in certain circumstances, such as if their number has been compromised by identity theft.

Frequently Asked Questions

Can I find out what my Social Security Number means based on the digits?

If your number was issued before 2011, the first three digits indicate the state where you registered for Social Security. You can look up which state corresponds to those digits on the SSA website. If your number was issued in 2011 or later, the digits are random and do not indicate anything about you or where you live.

Why does the SSA still use nine digits if there are only about 330 million people in the U.S.?

Nine digits can generate over one billion combinations, which provides a large buffer for growth and allows the SSA to avoid reusing numbers. The SSA has stated that the current supply of numbers is sufficient for the foreseeable future. Changing the format would require updating systems across the entire financial and government sector, which would be extremely costly and disruptive.

Did babies get Social Security Numbers before 1961?

No. Before 1961, Social Security Numbers were issued only to workers. Children and non-workers did not receive numbers unless they later became employed. The SSA began issuing numbers to children in 1961 when the Internal Revenue Service needed a way to identify dependents on tax returns.

Is a Social Security Number the same as a taxpayer identification number?

No, they are different. A Social Security Number is issued by the SSA to individuals for Social Security purposes. A taxpayer identification number (also called an Individual Taxpayer Identification Number or ITIN) is issued by the Internal Revenue Service to people who need to file taxes but do not have a Social Security Number, such as some non-citizens.