Amends title II (Old Age, Survivors, and Disability Insurance) (OASDI) of the Social Security Act with respect to the nine-month minimum duration of a marriage required to qualify a surviving spouse for OASDI benefits. Allows a less than nine-month duration of a marriage in the case of widows or widowers whose marriage was postponed by legal impediments to the marriage caused by State restrictions on divorce from a prior spouse institutionalized due to mental incompetence or similar incapacity.