If my son was 17 , but went to high school and did not have a job, why can't i claim him as a child credit

[Hal_Al · Accepted solution]

 That's how congress wrote the law.

Your child is  too old (over 16).You can still claim your child, as a dependent.  What you can't claim is the Child tax credit. This comes as a big surprise to many parents the year their child turns 17. A child over age 16 no longer qualifies for the Child Tax credit (CTC). Although a child can still be a student dependent through age 23, and a qualifying child for EIC,  the Child Tax Credit expires the year they turn 17 and you no longer get the $1000 CTC.