Here’s the sticky part in all of this. Yes federal law overrides state law HOWEVER IRS Form 14815 allows the use of a STATE divorce or custody order to prove the legal right to claim a dependent. Thereby the IRS is giving credence and i believe legal standing to a state order that allows said state order to trump federal law. If you can use your custody document in an audit for instance to prove the legal right to claim a child on taxes and the IRS accepts this as proof that implies that the court order trumps the over 50% rule. I would imagine the IRS does this to ensure you don’t have a bunch of rogue parents doing whatever they want and bogging the IRS down with reports of fraud etc. Also in the case of joint custody you would get into getting down to half a day to determine the “over 50% of the time”.
