Q. Can I claim him as a dependent?
A. No. His $40K income from part time work disqualifies him.
There are two types of dependents, "Qualifying Children"(QC) and Other ("Qualifying Relative" in IRS parlance even though they don't have to actually be related). There is no income limit for a QC but there is an age limit, student status, a relationship test and residence test.
Turning 24 in 2024 disqualifies him from being a QC. The rules for a qualifying relative do have an income test and it is only $5050. So, he cannot be QR either.
See full dependent rules at: https://turbotax.intuit.com/tax-tools/tax-tips/Family/Rules-for-Claiming-a-Dependent-on-Your-Tax-Ret...
Q. But, he's right on the border of how they define dependents?
A. It's all or nothing. And it's nothing in your case.
Q. Should I claim him as a dependent to get the tuition benefit and beg forgiveness if I've done it the wrong way?
A. No, not with the IRS. If you're saying your employer requires your adult child to be your tax dependent to qualify for the employee tuition benefit, you should review that with them for any flexibility in the rules. But, I would think not.
