To be eligible for a marriage-based green card, the applicant must have a U.S. financial sponsor (usually the sponsoring spouse) who certifies in an Affidavit of Support (Form I-864) that their annual income is at least 125% of the Federal Poverty Guidelines (100% for military sponsors). The exact minimum income required — most commonly $21,137 for a couple with no children — depends on where the sponsor lives, the size of their household, and other factors.