Social Security pays generous benefits to spouses. Because of this, the Social Security Administration has to fight marriage fraud in order to keep the finances of the Social Security program viable.
In the following video, Dan Caplinger, The Motley Fool's director of investment planning, looks at why marriage fraud is such a huge threat. Dan notes that there's a big financial incentive for retirees to get married if they aren't already, as spouses qualify for spousal benefits after just one year of marriage and for survivors' benefits after just nine months. In return, spouses can get a lifetime of Social Security benefits, even if they wouldn't qualify for any based on their own record. Dan points out that most fraud detection efforts center on marriages that weren't legal, but he concludes that even legally binding marriages could eventually pose a financial threat to the program if they're done only with Social Security benefits in mind.