@bgoodreau01 rather than getting twisted up in the words and everyone's varying responses, best to go the source document and determine for yourself. The child would need this completed worksheet in any event if every audited to defend that he is NOT required to file Kiddie Tax.
The IRS has a very specific definition of "support" and it may includes expenses of support you may not be considering. It is not just the child expenses for the portion of the year living on his own. It's the whole year, including the child's fair share of the parent's housing costs (which surprises many).
the definition of "support" is the worksheet on page 16. "earned income" is the income that requires labor, so the IRA distribution is not part of "earned income" (it is 'unearned income")
the only way to determine wherther his earned income exceeds half his support is to complete the worksheet. there is not enough information provided in your post to determine that his earned incomes exceeds half his FULL YEAR support.
https://www.irs.gov/pub/irs-pdf/p501.pdf
further, the instructions for the kiddie tax form 8815 refered to the SAME worksheet in publication 501. "support" is discussed on the bottom left of page 1 and refers publication 501.
https://www.irs.gov/pub/irs-pdf/i8615.pdf
does that help?
