Starting January 1, 2016, customers who wish to file Form I-290B, Notice of Motion or Appeal, in response to a decision on their Form N-600 or N-600K must mail their Form I-290B to the Chicago Lockbox. USCIS will no longer accept these forms at local field offices.

Customers should mail their Form I-290B for Form N-600 or N-600K to:

U.S. Postal ServiceUSPS Express Mail/Courier
P.O. Box 805887
Chicago, IL 60680-4120
Attn: FBAS
131 S. Dearborn, 3rd Floor
Chicago, IL 60603-5517

USCIS will provide a 30 day grace period from January 1-30, 2016, for customers who file their Form I 290B with the local office. Local field offices who receive Form I-290Bs during this time will forward the forms to the Chicago Lockbox.

After January 30, 2016, local field offices will return all Form I-290Bs for Forms N-600 or N-600K they receive and advise customers to file at the Chicago Lockbox.