How is child support calculated in Missouri?

Using Form 14, the mandatory Missouri Child Support Guidelines Worksheet governed by RSMo 452.340 and Missouri Supreme Court Rule 88.01. Both parents' monthly gross incomes are combined, the basic obligation is looked up on the Schedule of Basic Child Support Obligations, and it's split proportionally, with adjustments for health insurance, childcare, and parenting time.

Is Form 14 legally binding on the court?

The Form 14 amount creates a rebuttable presumption that it's the correct support amount. Use of Form 14 is mandatory in any divorce, child support action, or paternity proceeding, a judge must consider it even when deciding to deviate from it.

What changed with the 2026 Form 14 update?

The Missouri Supreme Court issued an updated Form 14 on March 4, 2025, effective January 1, 2026, including an updated Schedule of Basic Child Support Obligations reflecting current economic data.

How do I request a modification in Missouri?

Either parent can petition under RSMo 452.370 by showing a substantial and continuing change in circumstances. Missouri applies a 20% rule: if the current Form 14 guidelines produce an amount that differs from the existing order by 20% or more, the court presumes a modification is warranted.

How is child support enforced in Missouri?

If the paying parent becomes delinquent by an amount equal to one month's total obligation, their income becomes subject to withholding without further notice, including an additional 50% above the ordered amount to help pay down the arrears. The Family Support Division can also pursue tax refund, unemployment benefit, and lottery winnings interception, plus property liens, without going to court.

Missouri, United States

Missouri Child Support: A Parent's Guide

How child support works in Missouri, in plain English: the Form 14 income shares worksheet, modification, and enforcement.

Legal sources reviewed: August 10, 2026

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In short: Missouri's mandatory Form 14 worksheet, updated for January 1, 2026, produces a rebuttable presumptive support amount under the income shares model. A 20% difference between the current order and a fresh Form 14 calculation presumptively justifies a modification, and falling one month behind triggers automatic withholding, including an extra 50% toward arrears.

This is an educational overview written for parents, not lawyers. It isn't legal advice. For anything beyond general understanding, talk to a licensed Missouri family law attorney.

What Missouri generally provides

Missouri calculates child support using Form 14, the standardized worksheet governed by RSMo 452.340 and Missouri Supreme Court Rule 88.01. The court combines both parents' monthly gross incomes, looks up the basic obligation on the Schedule of Basic Child Support Obligations for the number of children, and splits it proportionally between the parents.

Important terminology

Form 14: Missouri's mandatory child support guidelines worksheet, producing a legally presumptive support amount.
Rebuttable presumption: the Form 14 amount is presumed correct, though a court can deviate from it with sufficient justification, considering the form regardless.
20% rule: the general threshold at which a recalculated Form 14 amount presumptively justifies modifying an existing order.

How the calculation works

Combining income and applying the schedule

Form 14 combines both parents' monthly gross incomes, references the Schedule of Basic Child Support Obligations for the number of children, divides the resulting obligation proportionally between the parents, and adds adjustments for health insurance, childcare, and parenting time credits.

The 2026 update

The Missouri Supreme Court issued an updated Form 14 on March 4, 2025, effective January 1, 2026, refreshing the Schedule of Basic Child Support Obligations with current economic data, meaning older calculations may no longer reflect the actual current guideline amounts.

A rebuttable presumption, not an absolute rule

The Form 14 amount is a rebuttable presumption of the correct support figure, mandatory in any divorce, child support, or paternity proceeding. A judge must consider it even when ultimately deciding to deviate from it for a specific reason.

Requesting or defending a modification

Either parent can petition for a modification under RSMo 452.370 by showing a substantial and continuing change in circumstances. Missouri's 20% rule provides an objective benchmark: if the current Form 14 guidelines produce an amount that differs from the existing order by 20% or more, the court presumes a modification is warranted. See the child support calculator and guideline finder for jurisdiction-specific calculation sources and guidance.

How enforcement works

If the paying parent becomes delinquent by an amount equal to one month's total support obligation, their income becomes subject to withholding without further notice, and that withholding includes an additional 50% above the ordered support amount, applied toward the unpaid arrears owed to the receiving parent. If income wasn't already being withheld at the order's effective date, it becomes subject to withholding automatically once the obligor becomes delinquent. Beyond wage withholding, Missouri's Family Support Division can pursue tax refund interception, unemployment benefits interception, lottery winnings interception, and property liens, all without requiring a separate court proceeding.

Common questions

Does my old Form 14 calculation still reflect current guidelines? Not necessarily, if it predates the January 1, 2026 update, the Schedule of Basic Child Support Obligations has since been refreshed, worth rerunning the calculation if it's been a while.

How quickly can withholding escalate? Fairly quickly, one month's worth of missed support triggers automatic withholding, with an extra 50% added specifically to address the arrears.

What if my co-parent isn't paying? Contact the Family Support Division, which can act on several enforcement tools without needing to first go to court.

Practical considerations

Because Missouri's 20% rule gives a concrete, calculable threshold for modification, running a fresh Form 14 worksheet periodically, especially after a real income change, is a practical way to check whether you have solid grounds before filing. For the custody arrangements that feed into the parenting-time credits on Form 14, see the Missouri custody guide.

Official Missouri resources

FAQ

Questions, answered

This information is provided for educational purposes only and is not legal advice. Family law varies by individual circumstances and may change over time. Consult a qualified attorney or appropriate official resource for advice about your situation.