Renewing a Visa
The visa stamp in your passport tells you when and how often you can enter the U.S., but it does not govern your authorized period of stay in the country. You can be in the U.S. beyond the expiration of the visa stamp, so long as your immigration status and I-94 record of arrival remain valid.
If you wish to travel outside the U.S. after your visa has expired, you do need to apply for and obtain a new visa stamp in your passport before you can reenter the country. Renewal applications cannot be done in the U.S.
If you are planning international travel to a third country, you may be required to show evidence that you have a valid U.S. visa stamp for reentry to the U.S. Check the travel requirements for your destination countries in advance, in case you need to renew your U.S. visa stamp prior to traveling to a third country
In Your Home Country
We recommend applying for the visa stamp at the Embassy or Consulate in your home country. If your visa application experiences delays, it is usually best to be in your country while you wait for the visa to be issued.
Applying to Renew a Visa
Some consular posts will accept applications from third country nationals. Review the information on the post's website to determine whether you can apply to renew your visa. Also check whether, based on your citizenship, you must apply for a visitor visa to enter that country.