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