No. A USCIS Number is not the same as a Social Security Number. Both are nine digits long, and that surface similarity is where the resemblance ends. They come from different agencies, they exist for different reasons, and they appear in different places on different documents. If you are a non-citizen, you may well have both, and each one does a job the other cannot do.
What the USCIS Number Is
The USCIS Number is a unique identifier the Department of Homeland Security assigns to non-citizens. You will also see it called the Alien Registration Number, or A-Number. For practical purposes those terms point to the same number: the A-Number is the letter “A” followed by seven to nine digits, and the USCIS Number is the digit string that follows the “A.”1U.S. Citizenship and Immigration Services. USCIS Number If your A-Number is shorter than nine digits, you pad it with a leading zero after the “A” to reach nine.2U.S. Citizenship and Immigration Services. Immigrant Fee Payment: Tips on Finding Your A-Number and DOS Case ID
The number’s job is to link your immigration records. Green Card applications, work authorization requests, and later a naturalization file all connect through the same A-Number. Once assigned, it stays with you for life, even after you become a U.S. citizen.
What the Social Security Number Is
The Social Security Number is a nine-digit identifier issued by the Social Security Administration. You need one to file federal taxes, start a job, open a bank account, apply for a loan, and claim government benefits.3Social Security Administration. Request a Social Security Number for the First Time The IRS treats the SSN as the standard taxpayer identification number for most individuals.4Internal Revenue Service. Taxpayer Identification Numbers (TIN)
Unlike the USCIS Number, the SSN is not limited to non-citizens. U.S. citizens, permanent residents, and non-citizens with work authorization can all receive one. Like the USCIS Number, an SSN is generally assigned for life.
The Differences at a Glance
Both numbers are nine digits. Almost everything else is different.
- Issuing agency. The USCIS Number comes from the Department of Homeland Security. The SSN comes from the Social Security Administration.
- Who gets one. Only non-citizens are assigned a USCIS Number. Both citizens and eligible non-citizens receive SSNs.5Social Security Administration. Social Security Numbers for Noncitizens
- Format. The A-Number carries a letter “A” prefix followed by seven to nine digits. The SSN is nine digits and nothing else.6U.S. Citizenship and Immigration Services. A-Number/Alien Registration Number/Alien Number (A-Number or A#)
- Purpose. The USCIS Number ties your immigration records together. The SSN tracks earnings, tax obligations, and benefit eligibility.
Because both numbers are nine digits, it is easy to type one into the wrong field. Form I-9, for instance, feeds into E-Verify, which checks employment eligibility against both DHS and SSA records.7E-Verify. What Is E-Verify Putting a USCIS Number where an SSN belongs, or the reverse, produces a mismatch.
Where to Find Each Number on Your Documents
On a Permanent Resident Card issued after May 10, 2010, your USCIS Number is printed on the front of the card.1U.S. Citizenship and Immigration Services. USCIS Number On an Employment Authorization Document, the front shows both your A-Number and a separate 13-character document number.8U.S. Citizenship and Immigration Services. 13.1 List A Documents That Establish Identity and Employment Authorization The document number identifies the physical card and changes when the card is replaced. The USCIS Number does not.
Your SSN appears on your Social Security card, on tax filings, and on wage records. The card itself comes in three versions depending on immigration status: an unrestricted card for citizens and permanent residents, a card marked “Valid for work only with DHS authorization” for non-citizens with temporary work authorization, and a card marked “Not valid for employment” for those who received a non-work SSN.9Social Security Administration. Types of Social Security Cards Employers rely on the annotation when checking work eligibility, and a “not valid for employment” card will not satisfy Form I-9.
Can a Non-Citizen Have Both Numbers?
Yes, and many do. Having a USCIS Number does not give you an SSN, and needing an SSN does not replace or duplicate your immigration file. There are three main paths.
Requesting an SSN Before You Arrive
If you are coming to the United States as a new immigrant on a visa processed through the Department of State, you can request an SSN on Form DS-260. Customs and Border Protection sends your entry information to USCIS, which passes it to SSA. Your card should arrive at your U.S. address within about three weeks of your admission, with no separate SSA visit needed.10Social Security Administration. POMS: RM 10205.600 – Enumeration-at-Entry
Requesting an SSN With a Work Permit
If you are applying for work authorization from inside the United States, Form I-765 has a section for requesting an SSN card at the same time. Once your EAD is approved, the Social Security card should follow within 14 days. If it does not arrive, contact your local Social Security office.11Social Security Administration. Apply for Your Social Security Card While Applying for Your Work Permit, Lawful Permanent Residency, or U.S. Naturalization
Non-Work SSNs
SSA generally issues SSNs only to non-citizens with DHS work authorization. The exception is when a federal statute specifically requires an SSN to receive a benefit, such as certain Social Security, Medicare, Medicaid, or Temporary Assistance for Needy Families payments. In those cases, SSA can assign a non-work SSN.5Social Security Administration. Social Security Numbers for Noncitizens12Social Security Administration. POMS: Valid Reasons to Assign an SSN for Nonwork Purposes
The ITIN: A Third Number That Is Neither
If you need to file a U.S. tax return but you are not eligible for an SSN, the IRS issues an Individual Taxpayer Identification Number. The ITIN is a nine-digit number that begins with 9 and exists only for federal tax purposes.13Internal Revenue Service. Topic No. 857, Individual Taxpayer Identification Number (ITIN) It does not authorize work, does not entitle you to Social Security benefits, and does not affect your immigration status. You apply for one on IRS Form W-7.14Internal Revenue Service. Instructions for Form W-7
So the full picture for many non-citizens is three separate nine-digit numbers from three separate agencies: a USCIS Number from DHS for your immigration file, an SSN from SSA for work and benefits, and possibly an ITIN from the IRS for taxes when an SSN is not available. None of them substitutes for another, and each one belongs in its own field on any form that asks for it.