These additional financial sponsors also have to submit an Affidavit of Support, proof of their income, and proof of their legal status in the United States. In this post, we'll explore examples of proof of US domicile and the documents required to establish proof of domicile.If you want to sponsor someone for a family-based green card, you need to provide proof of a U.S. domicile in your Affidavit of Support (Form I-864). Instructions to Applicants to the M.D. program: This is a fillable PDF form. Please answer the following questions within the space. On Form I864, petitioners must prove that they have the ability to financially support the visa applicant(s) if necessary. Learn how to complete form I864EZ, the simplified affidavit of support form for immigration. Form I864, Affidavit of Support, needs to be filed DHS if you are a U.S. citizen or LPR planning to sponsor a spouse or family member.