Custodial parent
If you were the custodial parent, as defined below, you would get the exemption. If your ex was the custodial parent, he would be entitled to the exemption. If you were the custodial parent, I would suggest you take the exemption on your return. If the IRS later questions it, you can show that you were the custodial parent under the rules below, then you will get the exemption.
The parent who has custody of the child for the greater part of the year (the custodial parent) is generally treated as the parent who provides more than half of the child's support. It does not matter whether the custodial parent actually provided more than half of the support. Custody is usually determined by the terms of the most recent decree of divorce or separate maintenance, or a later custody decree. If there is no decree, use the written separation agreement. If neither a decree nor agreement establishes custody, then the parent who has the physical custody of the child for the greater part of the year is considered to have custody of the child.
The noncustodial parent will be treated as providing more than half of the child's support if:
1) The custodial parent signs a written declaration that he or she will not claim the exemption for the child, and the noncustodial parent attaches this writ-ten declaration to his or her return,
2) A decree or agreement went into effect after 1984 and states the noncustodial parent can claim the child as a dependent without regard to any condition, such as payment of support, or
3) A decree or agreement executed be-fore 1985 provides that the noncustodial parent is entitled to the exemption, and he or she provides at least $600 for the child's support during the year, unless the pre-1985 decree or agreement is modified after 1984 to specify that this provision will not apply.
