A qualifying child is usually a child under 19 who lives with you most of the year, or a child under 24 who is enrolled in school full time at least 5 months of the year. A child of any age who is permanently or temporarily disabled also meets the requirements.  To be a qualifying child, your child must be your: - Son, daughter, stepchild, adopted child or foster child - Brother, sister, half-brother, half-sister, stepsister or stepbrother - Grandchild, niece or nephew Your child must have a SSN OR an ITIN in order for you to claim them on your tax return. You can apply for an ITIN for your child using form W7 when you file your taxes.  Learn more about qualifying children here on the IRS website.