If the current US residential address is also the current mailing address, check the "Is Mailing" attribute in the current US residentail address entered in the Contact Info tab of the individual record.  If the mailing address is not the current US residential address, add a mailing address in the Contact Info tab of the individual record,  select Address Type "Mailing Only", and check the "Is Mailing" attribute.  If you have already created your form, be sure to click the Refresh icon in the form to autopopulate the mailing address you just added.