20 CFR 222.17: “Child in care” when child of the employee is living with the claimant.

“Child in care” means a child who has been living with the claimant for at least 30 consecutive days unless—

(a) The child is in active military service;

(b) The child is 18 years old or older and is not disabled;

(c) The child is 18 years old or older with a mental disability and the claimant does not exercise parental control and responsibility; or

(d) The child is 18 years old or older with a physical disability, but it is not necessary for the claimant to perform personal services for the child.

(e) Parental control and responsibility for the care and welfare of the child means that the parent supervises the child's activities and makes important decisions about the child's needs either alone or with another person. Personal services are services such as dressing, feeding and managing money which the child cannot do alone because of a disability.