How Does Child Support Work with Joint Custody?

By Travis Gray, J.D.

How Does Child Support Work with Joint Custody?

By Travis Gray, J.D.

The guidelines for determining the amount of child support to be paid, if any, can vary by state. All states weigh the amount of time each parent has physical custody of a child but they diverge when determining how the amount of time spent with the child should affect child support payments. What's more, states vary when taking into consideration the income of both parents.

Documents labeled "joint custody" on a desk

While it is possible to alter the terms of your child support arrangement after a divorce decree is finalized, your best chance at a fair arrangement is by making your best case during your divorce. Success during your divorce hearing can go a long way in limiting your financial complications in the future.

Legal vs. Physical Custody

The two main types of custody. Legal custody gives a parent the right to have a say in the health and educational decisions of a child. Physical custody, on the other hand, involves the daily care of a child, as well as responsibilities for the decisions and expenses that go with it.

The court may award legal and physical custody to one or both parents. When the court awards either of these to both parents, it is known as joint custody. So, the arrangement in which the parents alternate days caring for their child is called joint physical custody and it plays a major role in child support determinations.

Child Support Formulas

There are two models used in determining the necessity of child support payments for parents with joint physical custody. These models are known as the income shares model and the percentage of income model. While it may seem natural to assign the expenses of raising a child evenly between two parents that share joint physical custody, the reality is that in many cases a parent may be required to pay a larger portion the expenses despite having the same number of overnights with the child.

Income Shares Model

The vast majority of states have adopted what is known as the income shares model. According to this model, a judge determines child support by combining the incomes of both parents and using the percentage of each parent's share of the income to determine their child support duty. For example, if the father earned $66,000 per year and the mother earned $33,000 per year, the father would be responsible for 66% of the child's expenses while the mother would be responsible for 33%.

However, the amount the parent owes is adjusted depending on the number of overnights the parent spends with the child per month. The theory is that with more overnights, the parent pays more expenses pays directly so less support is required of them.

Percentage of Income Model

A minority of states and the District of Columbia operate under the percentage of income model. Under this theory, the divorce court only takes into consideration the income for the parent that is required to pay child support. Known as the obligor, the parent that pays child support is required to pay a certain percentage of their total income.

This model differs in cases of joint physical custody. Some states take into account the number of overnights with a child and adjust the percentage of income required to be paid accordingly. However, other states ignore joint custody arrangements entirely. The end result in these circumstances is a parent that pays a hefty portion of their income towards child support despite caring for the child roughly half the time.

In most cases, you can expect your potential child support payments to decrease if the number of overnights with your child increases. Still, depending on which model your state uses to calculate child support, your state may only consider each parent's income rather than also considering the amount of time spent with your child.

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