U.S. Citizenship and Immigrations Services (USCIS) announced publication of a Federal Register Notice that expands the Direct Mail program to include Form N-400, Application for Naturalization.  The notice advises the public to file non-military N-400 applications with the appropriate Lockbox and provides a 30-day transition period whereby the Service Centers will forward any N-400 applications received at their facilities to the appropriate Lockbox.  Applicants should continue to file Military N-400 cases at the Nebraska Service Center (NSC). 

Beginning on October 14, 2008, applicants must submit Form N-400 and related supplements to one of two new USCIS Lockbox facilities for initial processing, using the following addresses:

If You Reside In: 

Alaska, Arizona, California, Colorado, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, North Dakota, Ohio, Oregon, South Dakota, Utah, Washington, Wisconsin, Wyoming, Territory of Guam, Northern Mariana Islands 

File N-400 with:

USCIS Lockbox Facility, USCIS,
P.O. Box 21251
Phoenix, AZ 85036

Private Courier (non-USPS)
USCIS, Attn: N400
1820 E Skyharbor Circle
S. Floor 1, Phoenix, AZ 85036

If You Reside In:

Alabama, Arkansas, Connecticut, Delaware, DC, Florida, Georgia, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Mississippi, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Oklahoma, Pennsylvania, Puerto Rico, Rhode Island, South Carolina, Tennessee, Texas, Vermont, Virginia, West Virginia, U.S. Virgin Islands.

File N-400 with:

USCIS Lockbox Facility, USCIS,
P.O. Box 299026
Lewisville, TX 75029.

Private Courier (non-USPS)
USCIS, Attn: N400
2501 S. State Hwy 121, Bldg. 4
Lewisville, TX 75067.

USCIS notes that the N-400 form instructions have been updated to reflect the new filing procedures.