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The Chicago Lockbox (also known as USCIS Lockbox) is a filing address for certain USCIS applications.

For United State Postal Service (USPS), the address is:

USCIS
P.O. Box 805887
Chicago, IL 60680-4120

For Private Couriers (non-USPS), the address is:

USCIS
Attn: FBASI
427 S. LaSalle - 3rd Floor
Chicago, IL 60605-1029