U.S. Citizenship and Immigrations Services requires most family-based immigrants to fill out immigration form I-864. In addition, some employment-based immigrants must fill out the form, according to USCIS.
Immigration form I-864 allows prospective immigrants to show they have sufficient financial support available if they immigrate to the United States. As part of the form, prospective immigrants must provide the name and contact information for their immigration sponsor, as USCIS explains. Form I-864 has a fee attached if filed in the United States but not if filed in another country. The nine-page form is officially known as the Affidavit of Support Under Section 213A of the Act, and it is administered by the USCIS and Department of Homeland Security.