The child tax credit is a non-refundable tax credit for people who have a qualifying child. The credit is limited to $1,000 per qualifying child.

For the child tax credit, a qualifying child is a child, descendant, foster child, stepchild, sibling, step-sibling, or a descendant of any of these, and all of the following must be true:

• The child is a U.S. citizen, U.S. national, or resident of the U.S.
• The child is under the age of 17 at the end of the current tax year.
• The child provided less than half of his or her own support in the current tax year.
• The child lived with you for more than half of the current tax year.

A child is considered to have lived with you if the child was born or died in the current tax year and  lived with you the entire time he or she was alive. Temporary absences, including school, vacation, medical care, military service, or detention in a juvenile facility, count as time lived with you.

For this credit, earned income only includes taxable earned income and nontaxable combat pay. Earned income generally includes salaries, wages, tips, net earnings from self-employment and other employee pay that is taxable.

• You must have tax liability on line 46 of Form 1040, line 28 of Form 1040A, or line 43 of Form 1040NR. If the amount of the credit is more than your tax liability, you must reduce the amount of the credit to no more than your tax liability.
• If your modified adjusted gross income (MAGI) exceeds $110,000 for married filing jointly, $75,000 for single, head of household, or qualifying widow(er), or $55,000 for married filing separately you must reduce the amount of the credit.

For more information see IRS Publication 972.