I’m being told I’m not eligible for the child tax credit but my son just turned 18 this September

[DoninGA]

A child older than 16 in 2020 is not eligible for the child tax credit on a 2020 tax return.

A child older than 17 in 2021 is not eligible for the child tax credit on a 2021 tax return.

[VolvoGirl]

They had to be UNDER 17 on December 31, 2020.  He turned 17 in Sept 2020.  And look at it this way.... The year he was born in Sept you got the Child Tax Credit for the whole year, not just after he was born.  So it evens out.  

[xmasbaby0]

Q B3. Who is a “qualifying child” for purposes of the 2021 Child Tax Credit? (added June 14, 2021)

A3. For tax year 2021, a qualifying child is an individual who does not turn 18 before January 1, 2022, and who satisfies the following conditions:

1. The individual is the taxpayer’s son, daughter, stepchild, eligible foster child, brother, sister, stepbrother, stepsister, half-brother, half-sister, or a descendant of any of them (for example, a grandchild, niece, or nephew).
2. The individual does not provide more than one-half of his or her own support during 2021.
3. The individual lives with the taxpayer for more than one-half of tax year 2021. For exceptions to this requirement, see IRS Publication 972, Child Tax Credit and Credit for Other Dependents PDF.
4. The individual is properly claimed as the taxpayer’s dependent. For more information about how to properly claim an individual as a dependent, see IRS Publication 501, Dependents, Standard Deduction, and Filing Information. PDF
5. The individual does not file a joint return with the individual’s spouse for tax year 2021 or files it only to claim a refund of withheld income tax or estimated tax paid.
6. The individual was a U.S. citizen, U.S. national, or U.S. resident alien. For more information on this condition, see IRS Publication 519, U.S. Tax Guide for Aliens. PDF