Originally Posted by Wnhough
if his mother lives with you and she provides his support, she gets to claim him and you don't
"and she provides his support" is the crux. She is not providing a majority of the support when she pays no rent or utilities. I called the IRS. The first big point is: 1) Can I claim my daughter as a dependent? Because If I can, then I can claim my grandson too. My daughter is 23 and not a student so the answer is no. 2) If she claims him, I can't. Done. Over. The IRS won't look at who paid what or who contributed more. While I can claim him with her permission, if she doesn't agree she will win any tiebreaker decision.
I don't think this is fair to grandparents in this extended family environment, but that's what they said.