USCIS application procedures :
Extension of Temporary Stay
Apply today with our Extension of Temporary Stay Kit
Staying in the United States beyond the time period covered by a temporary visa is possible as long as the visa holder has a legitimate reason for doing so . The extension must be requested before the expiration date on the I-94 (Arrival/Departure Record) or I-20/IAP-66.
On the I94 card the agent records either a date or a "D/S" (duration of status). The date that appears on the Form I-94 is important as it indicates that beyond that time, one must apply for an extension to remain in the country legally. Permission to enter and/or remain in the United States and to extend stay in the United States is granted by the USCIS, which is governed by the Department of Justice. The Department of State has no authority to extend your stay or change the information or date on your Form I-94.
Visitors may apply to extend your stay only if: Lawfully admitted into the United States with a non-immigrant (temporary) visa, the non-immigrant visa status remains valid, and no crimes have been committed. However persons may not apply for an extension of stay if admitted to the United States in the following visa categories: VWPP - Visa Waiver Pilot Program , a crewman an alien in transit or in transit without a visa, a fiancé(e) of a U.S. citizen or dependent of a fiancé(e).
It is essential that the application for an extension of stay be submitted before the current authorized stay expiration date. The application and correct fee should be mailed to the USCIS Service Center that serves the area where you are temporarily living. The USCIS recommends that visitors file for extension of stay at least 45 days before the visa expiration and the appropriate USCIS Service Center must receive the application by the day the visa expires.