I'll assume you meet all other qualifications for claiming your son as a qualifying child. here are other requirements - Federal 1040:
1) must be under 24 and a full-time student (any part of 5 months during the year) to be a qualifying child (QC)
2) for a QC his income doesn't matter
3) the QC must not provide over 50% of his support. (doubtful that if his income is only $5K that would be more than 50% of support)
4) if married then he cannot file a joint return with his spouse unless there is no tax liability but merely filing to get a refund of taxes withheld)
so for federal purposes, he would qualify you for HOH if all these conditions are met
if California has different conditions, Turbotax will ask about them when you get to the state section.
you do not report his earned income on your return.
