Social Security number definition

A Social Security number (SSN) is a nine-digit number issued by the U.S. government to all U.S. citizens, permanent residents, and eligible temporary residents. It is an identifier for individuals within the United States that is necessary to obtain a job and other government benefits. A Social Security Number is used to track an individual's lifetime earnings and the number of years worked.

Employers use the SSN to report an employee’s income to the IRS and the Social Security Administration and to report state income tax. The information received by Social Security throughout an individual’s life is used to determine eligibility for benefits, like disability or retirement and, calculate benefits.

Types of Social Security Cards

Social security issues three types of cards, depending on the situation of the individual. The majority of U.S. citizens and U.S. permanent residents will be issued the standard Social Security Card which includes the cardholder's name and number.

There are also two restricted types of Social Security cards issued to temporary residents who have work authorization in the U.S. and another for those who are not allowed to work. These restricted Social Security Cards will indicate the holder’s situation with a "not valid for employment" or "valid for work only with DHS authorization" accordingly.

Why you need to apply for a Social Security Card

  • Applying for a passport
  • Obtaining a drivers license
  • Opening an account with any U.S. financial institution
  • Applying for certain types of public assistance such as unemployment benefits
  • Applying for a federal loan or federal student loan
  • Enrolling in Medicare
  • Filing your tax return
  • To apply for social security

How to find your Social Security Number

If you have a Social Security Number (SSN), you can find it on your Social Security Card or ask for it to your local SSA office. You may also find the number on bank statements, tax returns, W-2 forms and forms filed to the USCIS (U.S. Immigration and Citizenship Services).

However, if you do not have a Social Security number, you may generally answer “None” in the space provided on USCIS forms. Most individuals with nonimmigrant visas do not have Social Security numbers.

Read more: How to get a replacement social security card