Q. How do I qualified for that credit of him being still in school?
A. You just claim him as a dependent, to get the $500 "other dependent credit". Just enter his info, at the dependent screens, under personal info.
There are two types of dependents, "Qualifying Children"(QC) and Other ("Qualifying Relative" [QR] 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.
Being in High school allows him to continue being a QC, which means ther is no income limit to him being your dependent
