Child support is the part of a family law case that generates the most arguments and the least clear information. Here is how it actually works in Missouri, in plain language, including the one rule that decides whether an existing order can be changed.
What Is Child Support Under Missouri Law?
Child support is a court ordered payment from one parent to the other to help cover a child’s ordinary living costs, and in Missouri both parents remain financially responsible for their child regardless of the custody arrangement.
It is not a penalty and it is not a transfer of wealth between adults. It is a contribution toward the costs of raising a child, and it typically goes toward housing, food, clothing, healthcare, childcare and school expenses.
The rules come from two places working together. RSMo 452.340 is the child support statute, and the courts apply it alongside the applicable Missouri Supreme Court rules and the Form 14 worksheet. Our child support page covers how we handle these cases.
What Are the 5 Key Rules of Missouri Child Support?
Five things decide almost every child support question in Missouri.
- Both parents owe support. The obligation follows parentage, not the custody label, and a parent with substantial parenting time can still owe or receive support.
- There are two ways to get an order. Through the state administratively, or through the family court. Both produce a valid, enforceable order.
- The number starts from a worksheet, not from a judge’s instinct. Form 14 produces a presumed amount from both parents’ financial information.
- The presumed amount can be departed from. Where the worksheet result would be unjust or inappropriate, the court can order something different.
- Changing an order takes a substantial and continuing change. This is where the twenty percent rule lives, and it is covered further down.
How Do You Get a Child Support Order in Missouri?
You can go through the state’s child support program or through the family court, and which one fits depends on whether there is anything else in dispute.
What Does the State Child Support Program Do?
Missouri’s Family Support Division can establish and enforce a support order without anyone filing a court case.
You apply through the state’s child support services. The program can help locate a parent, establish paternity where legal fatherhood has not been sorted out, and start or enforce an order.
This route is usually cheaper and often faster than litigation. It fits best when support is the only thing at issue.
Where it gets harder is when the parents disagree about the inputs rather than the outcome. Disputes over how much someone actually earns, how many overnights each parent really has, or who pays for daycare and health insurance are the ones that stall an administrative case.
When Should Child Support Go Through the Family Court?
When support is tangled up with anything else, the court can settle all of it in one case instead of two.
Court ordered support usually rides along with another matter.
- A divorce or legal separation.
- A custody case.
- A paternity action.
- A motion to modify an existing order.
The practical advantage is that legal custody, physical custody, the parenting schedule, who covers medical costs and the support number all get decided by the same judge at the same time, with the same set of facts in front of them. The St. Louis County Family Court, and the courts in the City of St. Louis, St. Charles County and Jefferson County, handle combined custody and support matters as a matter of routine.
What Goes Into the Child Support Calculation?
Both parents’ income, the overnight schedule, and a short list of child specific costs.
Form 14 is the worksheet that produces the presumed amount. In broad terms it takes in three things.
- Each parent’s gross monthly income. Wages, bonuses, overtime, commissions and self employment income all feature. Income that is irregular or hard to document is the most commonly fought over part of any support case.
- The overnight schedule. How many nights a year the child spends with each parent affects the result, which is why parenting time arguments and support arguments tend to arrive together.
- Child specific costs. Health insurance premiums for the child, work related childcare, and uninsured medical costs.
The worksheet result is a presumed amount rather than a ceiling or a floor. A court can order something different where the guideline figure would be unjust or inappropriate on the facts.
We are not going to quote you a number here. Anyone who gives you a figure before seeing both parents’ income and the overnight count is guessing.
Why Do Child Support Cases Get Complicated?
Because two of the three inputs are contestable, and both of them are things people have strong feelings about.
What Happens When a Parent’s Income Is Hard to Pin Down?
The case slows down and the documents start to matter more than the arguments.
Self employment, business ownership, commission work, seasonal work and cash income all make the income line harder to establish. So does a claim that a parent is deliberately earning less than they could. These cases turn on tax returns, bank records and business books rather than on what either parent says.
What If the Parenting Schedule on Paper Is Not the Real One?
That gap is one of the most common fights in a support case.
Where the order says one thing and the children’s actual weeks look like another, both the schedule and the support number can be in play. It is worth raising early with documentation rather than late with recollection.
Can a Missouri Child Support Order Be Changed?
Yes, but only on a showing of changed circumstances that are both substantial and continuing.
RSMo 452.370 sets the standard. Support “may be modified only upon a showing of changed circumstances so substantial and continuing as to make the terms unreasonable.”
Both words carry weight. A change that is large but temporary, or permanent but small, generally will not do it.
What Is the 20 Percent Rule?
If rerunning the guidelines today would move the support amount by twenty percent or more, Missouri treats that as a prima facie showing that the standard has been met.
The statute says it directly. If applying “the child support guidelines and criteria set forth in section 452.340 and applicable supreme court rules to the financial circumstances of the parties would result in a change of child support from the existing amount by twenty percent or more, a prima facie showing has been made of a change of circumstances so substantial and continuing as to make the present terms unreasonable, if the existing amount was based upon the presumed amount pursuant to the child support guidelines.”
Read the last clause, because it is the catch. The twenty percent shortcut applies where **the existing amount was itself based on the guideline figure.** If your current order came out of a negotiated deviation rather than the worksheet, you do not get the shortcut and you are back to proving substantial and continuing the long way.
That single sentence is the most useful thing on this page. If your income or the other parent’s has moved meaningfully since the order was entered, rerunning the worksheet is the cheapest question you can ask.
Does the Old Order Still Apply While You Ask?
Yes. An existing order stays enforceable until a court changes it.
Paying less because you believe you are entitled to a modification creates arrears. File first, then pay the new number.
What Happens If Child Support Is Not Paid?
Missouri has real enforcement tools, and both the courts and the state agency can use them.
Missouri law provides for collection through the state’s child support program as well as enforcement in court. The specific remedies available in a given case depend on the circumstances and on which route the case is in, and the practical point is the same either way. Arrears do not go away on their own, and they get harder to deal with the longer they sit.
If you are behind, or if you are not being paid, raising it early is cheaper than raising it late. That is true on both sides of the case.
Who Can Help With Child Support in St. Louis?
The useful first step is running the worksheet on your actual numbers, because that tells you whether you have a case worth bringing.
Bardol Law Firm practices only family law, and we are in the Clayton, St. Louis City, St. Charles and Jefferson County courts regularly. Bring your last two years of tax returns, your recent pay information and your real overnight schedule, and we will tell you plainly where your number is likely to land and whether a modification is worth filing. Sometimes the honest answer is that it is not, and you are better off knowing that before you spend anything. Our other family law questions and answers cover the rest.
Every client gets a named paralegal on the file, and we generally return calls within one business day. Call 314.918.0100 or reach us through our contact page. Family Law, Simplified. Fill out the form or call to set up a consultation.
This page is general information about Missouri law and is not legal advice. Every case turns on its own facts. The choice of a lawyer is an important decision and should not be based solely upon advertisements.