Missouri Child Support Calculator

How is Child Support Calculated in Missouri?

Missouri calculates child support to ensure your children receive the same proportion of parental income they would have if you lived together. Governed by Missouri Supreme Court Rule 88.01, the court combines both your incomes, finds the total support obligation from a state schedule, and then divides that obligation between you based on your percentage of the combined income.

Understanding the MO Parenting Time Credit

In Missouri, shared parenting time reduces child support through a tiered parenting time credit rather than a separate formula. This adjustment, outlined in Civil Procedure Form No. 14, begins when the non-primary parent has the child for at least 36 overnights per year. The credit percentage increases at several tiers, such as 92, 110, and 143 overnights, to account for the costs associated with more parenting time.

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✓ Verified for Effective January 1, 2026 (2026 Schedule) • Reviewed October 2026 by Harmoney

Missouri Child Support Guidelines at a Glance

Guideline Model Income Shares Model
Governing Legal Authority Missouri Supreme Court Rule 88.01 / Form No. 14
Shared Custody Threshold Tiered credit starting at 36 overnights annually
Age Support Ends Age 18 or high school graduation, whichever is later (but no later than 21)
Modification Standard 20% Change in Support Amount or Substantial Change in Circumstances

Missouri Child Support FAQs


At what age does child support end in MO?

Child support in Missouri ends when a child turns 18 or graduates from high school, whichever occurs later, but support cannot extend past age 21 for this purpose. This extension is governed by Missouri Revised Statutes § 452.340 to ensure support continues while a child is completing their secondary education.

How is child support calculated if one parent is unemployed in MO?

Missouri courts will impute a potential income to an unemployed or underemployed parent unless their situation is temporary or for a good reason. This imputed income is based on the parent's work history, qualifications, and job opportunities in the community, as detailed in the instructions for Civil Procedure Form No. 14.

How do I modify a child support order in MO?

You can modify a Missouri child support order by showing a substantial and continuing change in circumstances, and a 20% or greater change in the calculated support amount is legally considered a sufficient basis to file for a modification. This threshold is established by Missouri Revised Statutes § 452.370 to ensure court orders reflect current financial realities.

Does MO child support cover college expenses?

A Missouri court can order a parent to pay for college expenses until the child is 21, but this support is not automatic or guaranteed. Under Missouri Revised Statutes § 452.340, the court may order post-secondary educational support if the child is enrolled, maintains good academic standing, and meets other specific criteria.

How does MO handle health insurance and childcare costs?

Health insurance premiums and necessary work-related childcare costs are added to the basic child support obligation and are divided between the parents in proportion to their incomes. This ensures both parents contribute fairly to these additional expenses as required by the guidelines on Missouri's Civil Procedure Form No. 14.