An Affidavit of Support is a document family-based immigrants must file when seeking to become permanent residents of the United States. An affidavit of support, (USCIS Form I-864), is required for all immediate relatives of US citizens and lawful permanent residents.How to fill out the Affidavit of Co-Habitant - New York Police Department? The Orange County Immigration Attorney can assist you in navigating the family-based immigration petition process. You must submit ALL the required documents. The application form must be completely filled out and legible. Filling out the Affidavit of Co-Habitant is straightforward. IMPORTANT — Read Instructions before completing this form. You must complete and file an immigrant petition- Form I-130 with the United States Citizenship and Immigration Services ( USCIS) on behalf of your spouse. It doesn't just have to be from the petitioner, the United States citizen, or lawful permanent resident.