The Alien Number, also known as the A-Number or “alien registration number,” is a unique nine-digit identification number assigned to immigrants in the United States by the U.S. Citizenship and Immigration Services (USCIS). Think of it as your personal ID within the U.S. immigration system. It functions similarly to a social security number or tax ID, but within the immigration context.

When applying for a marriage-based green card through Adjustment of Status (AOS), USCIS requires proof that the petitioner spouse (a U.S. citizen or permanent resident) has sufficient and stable income to financially support the immigrant spouse. The primary financial document is Form I-864, Affidavit of Support, but one of the most effective supporting documents to strengthen your case is an Employment Verification Letter. This letter helps USCIS confirm the sponsor’s curre

Adjustment of Status (AOS) allows eligible non-U.S. citizens already in the United States to apply for permanent residence without leaving the country. This method is one of the most common ways to obtain a green card for those who entered the U.S. on a temporary visa. In this guide, we break down who qualifies, how the Adjustment of Status process 2025 works, what documents you need, and which mistakes to avoid.