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. If you have a joint sponsor, the joint sponsor must also complete and sign USCIS Form I-864.If you have a joint sponsor, they must also complete Form I864. In this video we're going to show you how to complete an i 864 and affidavit of support that is needed as part of the package for an adjustment of status. You, the sponsor (petitioner), and the joint sponsor must complete Form I-864. See tips for completing Form I-864. The I-864 is an Affidavit of Support. If you signed an affidavit of support, State regulations require the county welfare department to review your income, resources, and property in deciding. The petitioning sponsor (or substitute sponsor, if applicable), and the joint sponsor must each complete a Form I864. This video will help you to fill out I-864 For Joint Sponsor.