IRS Uniform Definition of a Child

The IRS uses a uniform definition of a child, called a qualifying child, which is used to determine if the child is eligible for child-related tax benefits on a taxpayer’s return. While many things changed under tax reform, the definition of a qualifying child stays the same.

What about non-biological children?

• An adopted child – The child must be legally adopted or lawfully placed by an authorized agency. Adopted children are treated the same by the IRS as biological children.
• An eligible foster child – A child placed by an authorized agency or by a judgment, decree, or other order of any court of competent jurisdiction. For example, a child placed in your home through a local child welfare agency.

NOTE: Stepchildren are considered child of blood for purposes of meeting the Qualifying Child Test. 

The “Uniform Definition of a Child” is also the Qualifying Child Test

The child must meet the following requirements to be considered a “qualifying child” for tax benefits:

• Relationship Test – The child must be a son, daughter, stepchild, foster child, sibling, half-sibling, stepsibling, or be a descendant (like a grandchild or nephew).
• Age Test – The qualifying child must be younger than you and under age 19, under age 24 if a full-time student, or any age if permanently and totally disabled.
• Residency Test – The qualifying child must have the same main home as you for more than half the year.
• Support Test – The qualifying child must not provide more than half of their own support.
• Citizenship Test – The qualifying child must be a US citizen, a US resident, a US national, or a resident of Canada or Mexico.
• Joint Return Test – The qualifying child must not file a joint return unless there would be zero tax liability on both Married Filing Separate returns (the return for your child and the return for your child's spouse), and the joint return is filed only to receive a refund.

What if the child qualifies as a dependent for more than one person?

If a child is the qualifying child for you and another person, you will need to decide who will claim the tax benefits using that child. If both of you claim tax benefits using the same child, the IRS will apply the following tie-breaker rules to determine who can claim tax benefits using that child:

• If both of you are the parents:
  • The parent the child lived with more than half the year can claim the benefits.
  • If the child lived equally with both parents, the one with the higher income can claim the benefits.
• If only one of you is the child's parent, the parent can claim the benefits.
• If neither person is the child’s parent, the one with the higher income can claim the benefits.

If you are not the child's parent and the child is a qualifying child for both you and the parents, you may claim the child only if:

• Neither parent will be claiming the child and are not required to file a tax return.
• Your adjusted gross income is higher than the adjusted gross income of both parents.

You are not eligible for the Earned Income Tax Credit or the child tax credits in this situation.

Learn more about claiming dependents on your tax return.

What tax benefits are affected by the IRS’ definition of a child? 

A qualifying child is needed to claim these credits:

• Child Tax Credit (CTC) - A child is your qualifying child for the Child Tax Credit if they meet all the tests listed above except for the Age Test - the child must be under age 17. The child must be your dependent and you must be the custodial parent unless you gave the other parent the dependent claim on a Form 8332, Release/Revocation of Release of Claim to Exemption for Child by Custodial Parent. In this situation, the noncustodial parent, the one with the Form 8332, can not claim EITC using the dependent listed on the form.
• Additional Child Tax Credit (ACTC) – The Additional Child Tax Credit is a refundable credit that you may receive if your Child Tax Credit is greater than the total amount of income taxes you owe. You can use Schedule 8812 to determine if you qualify for this credit. This is the credit you can claim for a child listed on the Form 8332 received from the custodial parent.
• New Credit for Other Dependents (ODC) – If you have dependents who are not eligible for the child tax credits you may be eligible for a $500 fully nonrefundable credit for each one. Generally, all dependents that do not qualify for the child tax credits are qualified for the credit for other dependents.
• Earned Income Tax Credit (EITC) - A child is your qualifying child for the Earned Income Tax Credit if they meet all the Relationship, Age, and Residency Tests listed above. The Support Test does not apply. A qualifying child who is married must be your dependent or the dependent of their other parent.
• Credit for Child and Dependent Care Expenses - A child is your qualifying child for the credit for Child and Dependent Care Expenses if they meet all the tests listed above except for the Age Test. For this credit, the child must be under age 13; but may be any age if physically or mentally unable to care for themselves. Your spouse, or other dependent, who was physically or mentally not able to care for themselves may also qualify you for this credit.
• Dependent exemption - Under tax reform, the exemptions have been suspended through 2025.
• Head of Household filing status - Generally, if your child is a qualifying child they will qualify you for the Head of Household filing status. Also, you must:
  • Be single or considered unmarried
  • Pay more than half the cost of keeping up the main home where you live with your qualifying child

You can’t claim Head of Household with a dependent child who is in the custody of their other parent, even when you have a Form 8332.