The child tax credit is $3,600 per child 5 or younger, $3,000 for each child 6-17 and is refundable for 2021. The credit begins is subject to two phase-out calculations. The first phaseout can reduce the $1,600 increased amount for children 5 or under ($1,000 for children 6-17). The second phaseout can reduce the remaining credit below $2,000 per child.
The first phaseout reduction applies to the $1,600 (or $1,000) and is $50 for each $1,000 (or fraction thereof) by which your modified AGI exceeds your filing status threshold: MFJ-$150,000, HOH-$112,500 or Single/MFS-$75,000
The second phaseout reduction applies to the $2,000 and is $50 for each $1,000 (of fraction thereof) by which you modified AGI exceeds your filing status threshold: MFJ-$400,000 or All Others-$200,000.