Beginning July 1, 2010 all extensions and grandfathered cases of the I600A/I600 cases will be processed by NBC (National Benefits Center) instead of the local field offices. These changes are now reflected on the USCIS website. The local (state) USCIS offices will be mailing all I6000 cases to NBC and will mail letters to families explaining the new process.
Families filing extensions without a fee can mail their application/documents directly to NBC at the following address:
PO Box 8025
Lee’s Summit, Missouri 64002
Families filing an extension with a fee must mail their documents/application to the lockbox location for processing.
If using U.S. Postal Service:
PO Box 660087
Dallas, TX 75266
If using Courier services (UPS, FedEx, etc.):
2501 S. State Highway 121 Business, Suite 400
Lewisville, TX 75067
Families with questions on this process should call or email (NBC) USCIS. The contact information is as follows:
Phone Number: 877-424-8374