Us Social Security Admin 2101 Broadway Ave Yankton, SD 57078 Phone : (605) 665-6801 Us Social Security Admin Business Category Administration Of Social Human Resource & Income Maintenance Programs United States Government--yankton, Social Security Admin 121 W 3rd St Ste 101 Yankton, SD 57078 Phone : (605) 665-6801 Business Category Government Offices-Federal Administration Of Social Human Resource & Income Maintenance Programs Government Offices & Public Schools