O-1 Visa holders are eligible for a Social Security Number (SSN) and need one in order to be employed. O-3 visa holders are ineligible for Social Security Numbers as they are not authorized to accept employment.
In order to apply for a Social Security Number, you must take your passport, Form I-797 (O-1 approval notice) and Form I-94 to the Social Security Administration office at 10 Fawcett Street, 1st Floor, Cambridge. From the Harvard T station, take the #78 or #74 bus to Fawcett Street.
When to apply
You must have been in the Unites States for at least ten days. This waiting period assures that your record will have been updated in the government's database. In addition, you cannot apply for an SSN before the start date of your visa document (Form I-797).
At the Social Security Administration office, you must complete the SSN application form. You will receive notification of your SSN in the mail. The process usually takes four to eight weeks. If you have not heard within this time period, please contact the HIO. You may call the Social Security Administration at 1-800-772-1213 or visit the Social Security Administration website with any questions. Once you have obtained a U.S. Social Security Number, it is not necessary to apply for a new one if the employment changes. If you lose your SSN Card and need to apply for a replacement card, you must prove that you are employed in the United States at the time of your application.