1. The adjustment may be granted based upon a court order or agreement that the noncustodial parent is granted at least one hundred twenty-one (121) overnights of parenting time per twelve-month period with the children in the case under consideration.

2. Average parenting time. If there are multiple children for whom support is being calculated, and the parent seeking the parenting time adjustment is spending a different amount of time with each child, then an annual average of parenting time with all of the children shall be calculated.

1. If the parent receiving the parenting time adjustment is granted one hundred twenty-one (121) or more overnights of parenting time per twelve-month period with a child, or an average of one hundred twenty-one (121) overnights with all applicable children, a reduction to the child support obligation of the parent may be made as set forth in this section.

2. A parenting time adjustment shall be made to the base monthly child support obligation by the following formula: The total combined base monthly child support obligation shall be multiplied by a factor determined by the number of overnights granted to the noncustodial parent. The result shall be designated the adjusted combined child support obligation. In a case where the noncustodial parent is granted:

3. To determine the adjusted child support obligation of each parent, the adjusted combined child support obligation shall be divided between the parents in proportion to their respective adjusted gross incomes.

5. The parent owing the greater amount of base child support shall pay the difference between the two amounts as a child support order. In no event shall the provisions of this paragraph be construed to authorize or allow the payment of child support by a parent having more than two hundred five (205) overnights. In no event shall the amount of child support ordered to be paid by a parent exceed the amount which would otherwise be ordered if the parent was not eligible for the parenting time adjustment.

E. 1. Failure to exercise or exercising more than the number of overnights upon which the parenting time adjustment is based, is a material change of circumstances.

2. If the court finds that the obligor has failed to exercise a significant number of the overnights provided in the court order necessary to receive the parenting time adjustment, in a proceeding to modify the child support order, the court may establish the amount that the obligor has underpaid due to the application of the parenting time adjustment as a child support judgment that may be enforced in the same manner as any other child support judgment.

3. The court may rule that the obligor will not receive the parenting time adjustment for the next twelve-month period. After a twelve-month period during which the obligor did not receive the parenting time adjustment, the obligor may petition the court to modify the child support order. The obligor may be granted a prospective parenting time adjustment upon a showing that the obligor has actually exercised the threshold number of overnights in the preceding twelve (12) months. No retroactive modification or credit from the child support guidelines amount shall be granted based on this section.