Lack of evidence of a legitimate relationship is a common reason why U.S. Citizenship and Immigration Services (USCIS) rejects marriage green card applications. The government wants to see proof that the marriage is bona fide, and that the couple didn’t get married purely for immigration purposes — that is, to obtain a green card. We’ve put together a detailed guide that explains the different types of documents an applicant can provide as proof, as well as which documents are considered stronger vs. weaker evidence. If the couple is currently living apart, there’s a section with alternative forms of proof they can provide.