If a judge issues an order in a divorce directing which parent can claim which children as exemptions for the purposes of filing income tax returns, but the order is not based on where the child actually lives or who has supported the child, do the IRS guidelines supercede the court order? For example, mom has sole legal and physical custody of 2 children yet father gets to claim one of the children on his taxes as an exemption (child support is minimal and often in serious arrears - mom by in large is child's sole supporter). If the IRS guidelines supercede the court order, can I find proof of this for the judge to see? Thank you.

The court order is suppose to be followed as part of the divorce agreement and settlement, if you do not follow the agreement ( court order) you could be taken back to court for being in contempt. So if you need the court order changed to fit situations that have changed since the divorce, you will need to go back to court to get it changed.

No, the court order is not superseding the IRS requirements. As per IRS, a non custodial parent can claim a child if he/she attaches a copy of court order.

Agreed. The court order as it stands is legally binding to all parties.