The Child Tax Credit is being doubled for 2018
The Child Tax Credit is available to be claimed for qualified children under age 17. And you can claim it for all of your qualifying children in a given tax year. To be clear, the child must be under 17 at the end of the year to claim the credit.
For 2018, the recently passed GOP tax reform bill doubles the amount of the Child Tax Credit from $1,000 to $2,000 per qualifying child.