What is The Income Shares Model for Determining Child Support?

If you’re divorcing in the U.S. and have a child under 18, you are more than likely going to pay or receive child support going forward.

Agreements to forgo child support are rarely accepted by courts here. Financial support is seen as the child’s right, so parents cannot negotiate it away. (Agreements to pay a certain amount are often approved, but only if the amount is close to what the court would have ordered anyway.)

Using custody to avoid child support also tends to backfire. Even when parents split time with the child 50/50, one usually pays support due to uneven incomes or child-related expenses. 

Put simply, you should expect a child support arrangement. But which one will the court order?

The Income Shares Model

Of the 50 U.S. states, 44 use the income shares model (or a version of it) to set child support payments. The various formulas that follow this model ensure that children of divorced parents receive the same financial support they would if their parents were still together. 

If you live in Alaska, Mississippi, Nevada, North Dakota, Texas, or Wisconsin, your child support will be decided by a less-common method known as the percentage of income model. 

If you live in any other state, use the steps below to estimate your child support payment roughly. Remember that a judge only uses the result of their state’s formula as a guide. They can order a higher or lower payment based on your family’s circumstances.

Doing the Math

Step 1:

The first step in the income shares model is to check your state’s basic child support obligation table. This shows how much the government expects parents to spend on their children, depending on:

• How much the parents earn as a unit (i.e., their combined earnings);
• How many eligible children do they have together (generally, these are children under 18).

When calculating a parent’s income, subtract any child support they pay for other children and any spousal support they pay. Include any spousal support they receive.

For example, take parents who live in North Carolina, have two children, and make a total of $8,000 a month. Neither parent pays child support for other children or spousal support. They check North Carolina’s child support table to see that their basic child support obligation is $1,664.

If those parents had a third child or their income increased, their basic support obligation would go up.

Step 2:

Each parent is responsible for a portion of the basic support obligation based on how much they earn. For example, if one parent earns 70 per cent of the family’s combined income, that parent is responsible for 70 percent of the obligation.

This means your next step is to determine how much of the combined parental income each person earns. To do this, divide each person’s income by the total amount you and your co-parent earn.

In our example, the North Carolina mother makes $4,400 a month. She divides 4,400 by 8,000 and learns that she brings in 55 percent of the combined income.

Our North Carolina father makes $3,600 a month, which is 45 per cent of the combined income.  

Step 3: 

Now, multiply each parent’s percentage of the earnings (calculated in Step 2) by the basic support obligation (determined in Step 1). 

For example, our imaginary mother takes 55 percent of $1,631 to get $915.20. This is how much of the basic child support obligation she is responsible for. 

Our imaginary father is responsible for 45 percent, or $748.80.

Step 4:

Now that you have a rough idea of how much your state expects you to spend on your children, you need to consider parenting time. Each state handles this differently, so look at your local child support laws for specifics.

If one parent has sole physical custody, often the other parent pays the full amount calculated in Step 3 to the custodial parent. So if we imagine that our father has sole physical custody, the mother would pay $915.20 a month.

If parents share physical custody, the final calculations are more complicated. Usually, you multiply each parent’s basic support obligation by 1.5 to reflect that parenting in two households costs more than parenting in one. Then, many states multiply each parent’s new total by the other parent’s percentage of time with the child in a year. The parent with the higher basic obligation often pays the difference in the results to the other parent. 

Using this rule, our imaginary mom’s obligation would increase to $1,372.80 and our dad’s to $1,123.20. If we assume they each spend 50 percent of the year with their children, we can multiply both figures by .5. Subtracting the smaller result from the larger one, we find out that the mom would pay $124.80 a month ($686.40 minus $561.60).

Other formulas for taking parenting time into account are possible. Generally, the more parenting time you have, the less child support you pay (or, the more you receive). 

What To Expect In Your Case

The steps above give you a rough sense of how much a state using the income shares model will consider you are obligated to spend on your child before parenting expenses are considered. Use a child support calculator for your state, or talk to a lawyer for a more precise estimation.

Remember that even after your state’s formula gives you a monthly payment amount, the judge has the discretion to adjust the payment based on your family’s circumstances. 

Whatever your child support order turns out to be, always comply and remember that the court had your child’s needs in mind when it came up with that number.