20 CFR 404.725: Evidence of a valid ceremonial marriage.

(a) General. A valid ceremonial marriage is one that follows procedures set by law in the State or foreign country where it takes place. These procedures cover who may perform the marriage ceremony, what licenses or witnesses are needed, and similar rules. A ceremonial marriage can be one that follows certain tribal Indian custom, Chinese custom, or similar traditional procedures. We will ask for the evidence described in this section.

(b) Preferred evidence. Preferred evidence of a ceremonial marriage is—

(1) If you are applying for wife's or husband's benefits, signed statements from you and the insured about when and where the marriage took place. If you are applying for the lump-sum death payment as the widow or widower, your signed statement about when and where the marriage took place; or

(2) If you are applying for any other benefits or there is evidence causing some doubt about whether there was a ceremonial marriage: a copy of the public record of marriage or a certified statement as to the marriage; a copy of the religious record of marriage or a certified statement as to what the record shows; or the original marriage certificate.

(c) Other evidence of a ceremonial marriage. If preferred evidence of a ceremonial marriage cannot be obtained, we will ask you to explain why and to give us a signed statement of the clergyman or official who held the marriage ceremony, or other convincing evidence of the marriage.