Child Support Laws in Missouri

Like all other states in the U.S., Missouri has child support guidelines to give parents and judges a consistent way to calculate the appropriate amount of support for kids when their parents divorce or split up. Missouri's guidelines use the "income shares model," which aims toward providing the same level of total support children would receive if the family were still together—and then divides that amount between the parents based on their incomes.

That basic principle may seem simple, but the actual child support calculations can be complicated. The state does provide a worksheet with directions (more on that below), but those directions are also complex and not always easy to follow. Below, we'll explain how Missouri's guidelines work, what you'll need to know to get started, when the amount of support in your case might be different than the standard calculation, and how to get help with the process.

Who Pays Child Support in Missouri?

Both parents are legally obligated to support their children. When parents are divorced or separated, the question of who pays child support usually depends on their arrangements for physical custody (parenting time).

• Primary custody with one parent: When the children live with one parent most of the time, the other parent (the "noncustodial parent") usually pays child support. The guidelines assume that custodial parents meet their share of the overall support obligation by paying directly for their kids' daily needs, like food and housing. However, Missouri's guidelines include an adjustment to account for duplicated expenses when the children spend a certain amount of time with the noncustodial parent (more below on that adjustment).
• Equal shared custody: When the parents have equal (or roughly equal) parenting time, the parent with higher income generally will make support payments, unless that parent pays most of certain fixed expenses for the children.
• Split custody: When parents have split custody (meaning they both have at least one of their children primarily living with them), they'll have to do separate child support calculations for each household. Then the parent who has a higher support obligation will pay the difference to the other parent.

This means that before you can calculate child support, you'll need to work out a parenting agreement or have a judge decide on child custody for you.

How Missouri's Child Support Calculation Works

Here are the basic steps for calculating child support in Missouri:

• add up each parent's monthly gross income
• subtract certain support obligations to arrive at adjusted gross income
• find the basic child support obligation from the Missouri guideline schedule, based on the parents' combined adjusted gross income and the number of children being supported
• add certain allowed child-rearing costs
• determine each parent's share of the resulting combined child support costs based on their proportionate share of the combined adjusted gross income, and
• make an additional adjustment based on shared parenting time.

We'll explain more about these steps below.

What Counts as Income When Calculating Child Support in Missouri?

The first thing you need to do before you can calculate child support is to gather information about both parents' income. Gross income is any money or other financial benefit that has a positive impact on parents' ability to support their children, including:

• salaries, commissions, and severance pay
• income from self-employment, rents, or a business, less certain ordinary expenses needed to produce that income
• workers' compensation and disability benefits
• unemployment insurance benefits
• income from interest, dividends, annuities, and trusts
• military allowances for housing and food, and
• Social Security and other retirement benefits.

Depending on the circumstances, some other sources of money might be included in gross income when calculating child support, including overtime pay, bonuses, earnings from second jobs, recurring capital gains, prizes, and significant employment benefits. However, gross income will not include child support received for children from other relationships or means-tested public assistance (such as Medicaid, food stamps, or SSI benefits).

After adding up each parent's gross income, you can then make the following adjustments:

• add court-ordered maintenance (alimony) to the income of the parent who's receiving those payments, and subtract that amount from the income of the parent who's paying maintenance
• subtract child support that either parent is paying (under a court or administrative order) for children from another relationship
• subtract a parent's support obligation for natural or adopted children from other relationships who are primarily living with that parent (after deducting any child support being received for those children).

When "Imputed" Income May Be Used to Calculate Child Support in Missouri

Missouri's guidelines allow judges to impute income to unemployed or underemployed parents. That way, child support will be calculated based on what the parent could be earning. However, courts in Missouri have consistently held that judges shouldn't impute income if a parent's unemployment or underemployment is involuntary. (Lokeman v. Flattery, 146 S.W.3d 422 (Mo. Ct. App. 2004).)

When deciding whether to impute income to a parent—and if so, how much—judges will consider all of the relevant background circumstances, including:

• the parent's recent earnings and job history, education and other qualifications, record of looking for work, and employment barriers
• local employment opportunities and prevailing wages, and
• whether the parent is caring for a child under circumstances that make it appropriate not to require that parent to work outside the home.

Finding the Basic Support Obligation

Missouri provides a schedule that shows the total basic support amount (for both parents), before any further adjustments. Add up both parents' adjusted gross income, then find the closest number to that total in the first column of the table. Go across that row until you reach the column for the number of children you have.

When the appropriate boxes on the schedule are shaded, a low-income adjustment applies. In these cases, the basic support for the paying parent will be the lower of (1) a calculation using only the paying parent's income, or (2) the standard calculation using both parents' incomes.

Adjustments for Child Care and Health Expenses

Missouri's guidelines allow adjustments to the basic child support amount for the following expenses:

• reasonable work-related child care expenses (for both parents, when appropriate)
• the cost of health insurance premiums for the children
• unreimbursed or uninsured costs of medical and dental care for the children (over $250 per year per child), as long as those expenses are predictable and recurring, and a parent is required to pay them under a court order or the parents' agreement, and
• any other extraordinary child-related expenses that a parent must pay under a court order or agreement.

When the parent receiving support is entitled to the child care tax credit, the adjustment for child care expenses must account for that credit. The directions for the child support worksheet include a separate table and worksheet to calculate the effect of the credit on the net child care costs.

Calculating Each Parent's Share of the Total Child Support Obligation

To figure each parent's share of the total child support costs, divide each parent's adjusted gross income by their combined incomes. For example, say Parent A earns $6,000 a month in adjusted gross income, while Parent B earns $4,000. Parent A's share of their combined incomes is 60% ($6,000 divided by $10,000 = .6 or 60%), and Parent B's share is 40%. So Parent A would be responsible for 60% of the total combined child support costs shown on the worksheet, while Parent B's share would be 40% of that total.

Adjustment for Parenting Time

Missouri recognizes that noncustodial parents will have additional expenses the more parenting time they have with their kids, so the guidelines include an adjustment to child support based on the number of overnights the kids spend with the parent who's paying support. The adjustment begins at 6% for 36 nights a year and steps up in increments to a maximum of 34% for 181-183 overnights a year. However, if that adjustment would be unfair or inappropriate, the judge may decide to use a parenting time adjustment of up to 50%, based on the specific circumstances.

Generally, the parenting time adjustment won't apply when the income of the parent receiving support is below a certain level, but there are exceptions—including when the paying parent would also have little income left over after paying support.

When Child Support May Be Different Than the Standard Calculation

The amount of child support calculated under Missouri's guidelines is considered the "presumed" amount, meaning that courts assume it's the correct amount in any case. You may request a higher or lower amount (known as a "deviation"), but you'll need to convince a judge that the presumed amount would be unfair or inappropriate in your case.

When deciding whether to grant a deviation, the judge must consider all of the relevant circumstances, including:

• the financial resources and needs of both parents and the child
• the child's physical and emotional condition
• the child's educational needs, and
• the standard of living the child would have had if the family had stayed together.

(Mo. Rev. Stat. § 452.340 (2024).

Also, the guidelines include certain assumptions, including that the parent who's receiving support (usually the primary custodial parent) will claim the dependency exemption for the child on income tax returns. If a judge orders that the parent who's paying support is entitled to claim that exemption, that could be a reason for a deviation.

Parents may agree on an amount of child support, as long as they submit their agreement to the court along with the worksheet showing the guideline calculation. If they've agreed to a different amount, they'll also need to explain the reasons that the calculated amount would be unfair or inappropriate. A judge will review their paperwork before deciding whether to approve the agreement.

How to Modify Child Support in Missouri

You may request a change in the amount of child support you're currently paying or receiving if you can prove there's been a change in circumstances, and that the change is continuing and substantial enough to make the current amount unreasonable. The easiest way to meet this requirement is simply by showing that a new guideline calculation of support based on your current circumstances is 20% different than your existing support amount (as long as that amount wasn't a deviation from the presumed amount).

Otherwise, the judge will have to decide whether you qualify for a modification, after considering both parents' financial resources, including:

• whether a parent's new spouse (or another partner the parent is living with) is sharing their household expenses, and
• if either parent is unemployed, that parent's earning capacity.

Once you've met the changed-circumstances requirements for a modification, the judge will then decide on the appropriate new amount of support under the guidelines. (Mo. Rev. Stat. § 452.370 (2024).)

You may request a review of your existing support order from the Family Support Division (FSD) in Missouri's Department of Social Services. Generally, you're eligible for a review if it's been at least three years since your existing order was issued, previously reviewed, or modified—or if there are special circumstances in your case (such as when there's been a large change in a parent's income). You'll need to send a written request by mail (to the FSD, P.O. Box 6790, Jefferson City, MO 65102-6790) or by email (to [email protected]).

If the FSD review shows that you qualify for a modification, the agency will handle the request in court for you. Otherwise, you'll need to file a motion to modify child support directly with the court.

When Does Child Support End in Missouri?

In Missouri, child support generally ends when the child turns 18, joins the military, marries, or otherwise becomes emancipated. However, if the child is still in high school student after turning 18, the support obligation will continue until the child graduates or turns 21, whichever happens first.

Also, parents in Missouri will continue to be obligated to pay support for children up to age 21 when they're attending college or vocational school, as long as they give their parents transcripts or other proof that they meet the credit and grade requirements.

Finally, Missouri judges may order continuing child support for adult children who are physically or mentally incapacitated and can't support themselves.

(Mo. Rev. Stat. §§ 452.340.3, 452.370.4 (2024).)

Resources and Help With Child Support

Unlike many other states, Missouri doesn't provide an official child support calculator. You might find other so-called calculators online, but there's no guarantee that they're up-to-date or include all of the adjustments in Missouri's guidelines. To calculate support accurately, you'll need to use the state's official worksheet (SC 01 Form 14), the directions for completing the worksheet (CS 01 DIR, which includes the guidelines), and the schedule of basic child support obligations (CS 01 SCH). You can download all of these from the Missouri Court Child Support Forms page.

If you're a parent who's filing for divorce or legal separation in Missouri, child support will typically be handled as part of that legal process. Otherwise, anyone with custody of a child may apply for child support with Missouri's FSD. The agency can help with calculating child support based on the information you provide. FSD can also help enforce child support and will handle a modification request if you qualify (as discussed above).

If FSD isn't handling your case, you may need to speak with a lawyer to get expert assistance with child support—especially if you and your co-parent can't agree on a support amount or a modification request.