Many people ask us if they can call the National Customer Service Center (NCSC) to check on the status of their case. While you can call them they will only tell you the same information you can find in their online case tracking here.
The only time they will take your concerns to the Service Center to find out what is really happening is when your case goes 15 days beyond the stated processing time. You can find published processing time for your visa type here. Note however that the USCIS says these estimated processing times are already 45 days old by the time the are posted on the web site.
For example if your case was received on September 10 2010 and the stated processing time is 5 months the USCIS will not look into your situation until after February 25 2011 (5 months processing time plus 15 days overdue).
You can contact the NCSC at 1-800-375-5283. For TTD users call 800-767-1833. There is a dedicated help line for members of the military and their family at 877-247-4645.
For email enquires you can write the addresses below but don’t expect an answer unless your case is more than 15 days past the stated processing times:
California Service Center: firstname.lastname@example.org
Vermont Service Center: email@example.com
Nebraska Service Center: firstname.lastname@example.org
Texas Service Center: email@example.com
If you are in Canada write to USCIS.Canada@dhs.gov
If you do not receive a response within 21 days of contacting the appropriate Service Center (and your case is 15 days past-due) you can email the USCIS Headquarters Office of Service Center Operations by email at: SCOPSSCATA@dhs.gov. You will receive a response from this email address within ten days.
To see a more exhaustive list of ways to contact the USCIS go here.