If he has a W-2 that shows tax withheld in boxes 2 or 17 he can file to seek a refund. If no tax was withheld he does not need to file. You do not include his W-2 on your own tax return. You can still claim him as a dependent. Make sure if he files a tax return that he says on his own return that he can be claimed as someone else's dependent.
If the money he earned was reported on a 1099NEC---he is required to file and will have to pay self-employment tax for Social Security and Medicare. You might want to use the IRS Free File site in that situation so that you do not have to pay for the expensive self-employment software here.
https://www.irs.gov/filing/free-file-do-your-federal-taxes-for-free
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
