Please be sure to NOT enter his W-2 on YOUR tax return, whether he is your dependent or not.
If he/she is required to file, he/she should report his W-2 on his tax return and - if he/she is your dependent -the dependent must indicate on his tax return that he is being claimed by someone else. As a dependent, he/she is required to file if W2 income is more than $6300 for the year.
