404.1015—Family services.
(2)
You do nonbusiness work (see § 404.1058(a)(3) for an explanation of nonbusiness work) or perform domestic service (as described in § 404.1057(b)) as an employee of your parent while under age 21;
(4)
You perform domestic service in the private home of your son, daughter or spouse as an employee of that son, daughter or spouse unless—
(i)
The son or daughter has a child (either natural, adopted or stepchild) living in the home who is under age 18 or, if older, has a mental or physical condition that requires the personal care and supervision of an adult for at least four continuous weeks in the calendar quarter in which the work is done; and
(ii)
The son or daughter is a widower or widow, or is divorced and has not remarried, or has a spouse living in the home who, because of a physical or mental condition, is incapable of taking care of the child and the condition is present for at least four continuous weeks in the calendar quarter in which the work is done.
(b) Family work for other than sole proprietor.
Work for a corporation is not excluded under this section, and work for a partnership is not excluded unless the required family relationship exists between the employee and each of the partners.