Form I-864 is necessary for some employment-based immigrants and for most family-based preference immigrants and immediate relatives of U.S. citizens. The affidavit has to show that the mentioned immigrants’ categories have means of subsistence, adequate financial support, and that they will not rely on the U.S. government for financial support, or in other words, will not become a public charge.
This affidavit serves as a contract between a sponsor, or joint sponsors, and the U.S. government. By completing and signing Form I-864 a person becomes a sponsor. The sponsor must show on this affidavit that he/she has enough income and/or assets to maintain the intending immigrant and that he/she will financially support the immigrant named in this affidavit, in case it becomes necessary.
Meanwhile, please note that submission of Affidavit of Support may make the sponsored immigrant ineligible for certain federal, state, or local means-tested public benefits.