Using a law within Social Security that provides clear financial incentives to delay marriage, we estimate the financial value of a month of marriage. Specifically, the law provides that widows who are eligible for Social Security benefits on their deceased spouse’s earnings records are eligible for benefits at age 60, unless they remarry before that age. If they remarry before that age, they cannot claim widow benefits and must wait until at least age 62 to claim spousal benefits on their new husband’s record, which are typically less generous than widow benefits. To generate an estimate of what this behavior implies about the value of marriage, we use data from five panels of the Survey of Income and Program Participation linked to administrative data from Social Security. We estimate the cost of marrying before age 60 imposed by the Social Security program. We develop a model that reflects the institutional details of Social Security and generate a likelihood function that reflects that model. By taking advantage of the variation in these costs and when or whether widows remarry before age 60, we estimate the benefit of marriage to be $8000/month. These estimates appear to be reasonable in the context of the short length of time widows are willing to wait and the high value of Social Security benefits.