If you have never had a Social Security number (SSN)—meaning you were never assigned one at any point in your life—you need to apply for an original number. The process is similar to the process for getting a replacement card, but it must be done in person, and the ID requirement is stricter.
Gather the identifying documents you will need.
To get your SSN, you must prove your identity (a process called “enumeration”) with proof of: (1) your age; (2) your U.S. citizenship or legal presence; and (3) your identity.
For an original SSN, you must bring more than one document to prove this information (not just one primary ID document). However, the types of ID documents you can use as proof are the same as for getting a replacement card (see PG. 40). Some documents carry more weight than others: an authorized certified birth certificate (or proof of naturalization, hospital record, or religious record) will be the most important. Remember, the SSA Field Office reviewer has to decide that you are who you claim to be. Give him or her every reason to believe so, and bring as much proof as possible.
Find your local Social Security Administration Field Office or Card Center.
Go to the website https://secure.ssa.gov/ICON/main.jsp to locate a local SSA Field Office.
Go to your local SSA Field Office or Card Center and fill out the application (Form SS-5).Meet with an SSA employee to verify your identity.
Bring with you everything that could help prove who you are — even family members who can vouch for you (they must bring valid ID for themselves)! An SSA Field Office reviewer will interview you and review all the documents you bring. Depending on what you provide, the reviewer may ask for additional evidence of your age, citizenship/legal presence, or identity. The reviewer will enter all of your documentation into the SSA’s electronic application system. Generally, if the reviewer believes your documents are authentic and that you are who you say you are, your completed electronic application will be sent to a central office, and you’ll be issued a Social Security card within about 2 weeks. If your information needs to be verified, the process can take several weeks or months.