Is the USCIS number (USCIS#) on a green card a sensitive piece of information? If so, why?

I see that some people blurry it, e.g.:

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  • It's a unique ID number. i don't know whether it can be used in identity theft or other fraud, but it certainly seems right to blur it, at least in the name of erring on the side of caution.
    – phoog
    Commented Jul 7, 2016 at 21:26

1 Answer 1


The blurred out number is known as the "A" number or Alien Registration number. It's a unique number that USCIS gives a noncitizen when he or she applies for a benefit, such as a green card.


A person's A-number is like a person's social security number. It is considered to be sensitive personally identifiable information, which is information that, alone or in conjunction with other information, can be traced to the identity of an individual.

The A-number is linked to a person's application(s) for immigration benefits. Some of the information that the U.S. government requires a noncitizen to disclose in such an application is private and sensitive information that could be used to cause further harm to the person. For example, an applicant for permanent residency must share identifying information such as his social security number and mother's maiden name, as well as information about his medical history and finances. If the A-number is compromised, a person's privacy is compromised, and the information disclosed may cause harm, if not embarrassment, to the person. The USCIS #/A-number is blurred in order to protect the privacy of the individual.


  • 2
    This doesn't answer the question, which is whether that number is a "sensitive" piece of information, and, if so, why (that is, what harm could befall someone if a malicious person learns their A number)?
    – phoog
    Commented Oct 7, 2016 at 19:59
  • Thanks for the feedback! I updated the post with more specific info.
    – Sedna
    Commented Oct 11, 2016 at 12:19

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