(1) A total support amount is determined for each parent, separately, and consists of:

(a) the parent's share of the primary child support allowance, with supplemental needs, if any, plus the parent's standard of living adjustment; or

(b) the parent's minimum support obligation determined under ARM 37.62.126.

(2) After determining each parent's obligation according to (1)(a) or (1)(b), above, each parent's obligation is allocated according to the number of days each child spends with each parent.

(a) If all the children of the calculation reside primarily with one parent and do not spend more than 110 days per year with the other parent, the annual transfer payment, defined as the net amount of child support one parent owes the other, is the same as the total, annual support amount owed by the nonresidential parent.

(i) To set the amount of each child's monthly transfer payment, divide the annual transfer payment by the number of children in the calculation. Then, divide each child's annual payment by 12 and round the result according to ARM 37.62.134(2)(a)(ii), following.

(ii) The monthly transfer payment per child is rounded to whole dollars as follows: round down to the next whole dollar amounts ending in $0.49 or less and round up for amounts ending in $0.50 or more. The total of the rounded per child amount is the total monthly transfer payment owed by one parent to the other and/or to a third party, and due to rounding, may vary from the monthly transfer payment shown in the calculation.

(b) If any child of the calculation spends in excess of 110 days per year with both parents or if one or more children reside primarily with one parent while one or more children reside primarily with the other parent, the allocation of each parent's total support amount is determined as follows:

(i) recalculate the needs of each child separately;

(ii) recombine each parent's total support amount for each child based upon that child's proportionate need;

(iii) allocate the parent's total support amount for each child by retaining the amount for time the child spends with the parent and owing to the other parent the amount for time the child spends with the other parent;

(iv) offset the amounts each parent owes the other by subtracting the lower obligation from the higher for each of the children. The remaining balance for each child is the annual transfer payment for that child and is entered in the column of the parent owing the balance; and

(v) to set the monthly transfer payment, divide the annual transfer payment for each child by 12 and round according to (2)(a)(ii).

(A) where the calculation includes only one child, the monthly transfer payment is the total amount due from one parent to the other; or

(B) where the calculation includes two or more children, the monthly transfer payment for each child is the amount entered for the child at (2)(b)(v). The monthly transfer payment for each child is entered in the column of the parent owing the payment. Each parent's column is totaled and the difference between mother's total and father's total is the final monthly transfer payment owed by the parent with the higher total.