Use this form to show they have adequate means of financial support and are not likely to rely on the US government for financial support. Provide information about the beneficiary's income and assets.Each affidavit must contain the affiant's full name, address, date and place of birth, and signature. An affidavit of support form must be submitted together with supporting documents which establishes the income source and income amount listed on the form. Step 3: Complete Affidavit of Support and Financial Documentation. In this guide, we will explain who needs to complete Form I864, when to file it, and how to fill out Form I864 stepbystep. USCIS will research the non-citizen's records and complete the response portion of the form through the SAVE system within ten (10) working days of receipt. Option 1 or Option 2. The Affidavit of Support (Form I-864) is a key document in your green card case. Call MC Law Group or fill out the form on this website today to learn about our immigration services and receive legal advice.