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. In today's video we're going to fill out form i-864 the affidavit of support form together.It is one of the most confusing forms. An affidavit of support, (USCIS Form I-864), is required for all immediate relatives of US citizens and lawful permanent residents. Completing and signing Form I-864 makes you the sponsor. In this guide, we will explain who needs to complete Form I864, when to file it, and how to fill out Form I864 stepbystep. A) Complete an Affidavit of Support form and; b) Gather evidence of their finances and other supporting documents (See Step 5). Affidavit of Support (if you have a sponsor other than yourself). Affidavit of Support (if you have a sponsor other than yourself). Failure to complete and serve this form may result in sanctions consistent with MCR 2.313.