In the Indiana Parenting Time Guidelines it says that the parents should switch back and forth every year
What's fair is open to interpretation, and what's "fair" to one is likely to be considered unfair by the other. The statute used to equate claiming the exemption to the parent who paid the most support of the child. Now it is based on custody, with the custodial parent (the one with whom the child lives more than 1/2 of the year) the one to claim the exemption unless they transfer it to the other parent.
Obviously, local courts may write decrees to the contrary, but a local court decree is not binding on the federal Government. Consequently, if a local court decree is not followed, the recourse is through a local court order, not the IRS.
The "Indiana Parenting Time Guidelines" adopted by the Indiana Supreme Court are just that - guidelines, not mandatory rules, and are not binding on the IRS.
