Child Support Calculations in Missouri

Missouri uses the Income Shares model to calculate child support, governed by RSMo Chapter 452 and Supreme Court Rule 88.01. The guidelines use Form 14 to calculate the presumed child support amount. Whether you're navigating an uncontested or contested divorce, understanding how Missouri calculates child support is essential.

The Income Shares Model and Form 14

Missouri's Income Shares model determines the Presumed Child Support Amount (PCSA) using Form 14, which incorporates Schedule of Basic Child Support Obligations. The schedule provides amounts at income increments up to a combined monthly gross income of $30,000.

Above the cap: When combined gross income exceeds $30,000/month, the court uses its discretion considering the schedule's marginal rates and the child's reasonable needs. The Form 14 Directions note that the last applicable rate may be extended.

2026 Update: A new Form 14 became effective January 1, 2026, updating the schedule amounts and calculations.

Determining Gross Income

"Gross income" for Form 14 purposes includes income from all sources:

• Wages, salaries, commissions, bonuses, and tips
• Self-employment income (gross receipts minus ordinary and necessary expenses)
• Dividends, interest, royalties, and trust distributions
• Social Security benefits, pensions, and annuities
• Workers' compensation, disability, and unemployment benefits
• Spousal support received (support paid to a prior spouse is deducted)
• In-kind benefits that reduce personal living expenses

Excluded: Means-tested benefits (TANF, SSI, SNAP, public housing) are excluded from gross income. Child support received for other children is also excluded.

Imputation: Courts may impute income to a parent who is voluntarily unemployed or underemployed without good cause. Factors include employment history, education, age, health, and local job market conditions. Imputation is not appropriate for parents staying home to care for young children under certain circumstances.

Overnight Credit (Parenting Time Adjustment)

Missouri provides an overnight visitation credit using a stepped percentage table. The credit begins at 36 overnights per year:

• 36-49 overnights: 6% credit
• 50-59 overnights: 8% credit
• 60-71 overnights: 10% credit
• 72-85 overnights: 12% credit
• 86-99 overnights: 14% credit
• 100-109 overnights: 16% credit
• 110-120 overnights: 18% credit
• 121-131 overnights: 20% credit
• 132-143 overnights: 22% credit
• 144-157 overnights: 24% credit
• 158-167 overnights: 26% credit
• 168-175 overnights: 28% credit
• 176-180 overnights: 30% credit
• 181-183 overnights (equal time): 34% credit

Equal custody: At 181-183 overnights, each parent's share is calculated using the 34% credit. The parent with higher income pays the difference to the other parent.

Split custody: When each parent has physical custody of at least one child, Form 14 is completed separately for each child or group of children, then obligations are offset.

Estimate Your Missouri Child Support

Use our calculator to get a preliminary estimate. For official calculations, use the Missouri Courts Form 14.

Self-Support Reserve and Low-Income Cases

Missouri protects low-income obligors through a Self-Support Reserve (SSR):

• SSR amount: Approximately $990/month (based on 2016 federal poverty guideline for one person, adjusted)
• Low-income adjustment: When the obligor's income minus the calculated support would fall below the SSR, the obligation is reduced
• Minimum order: Courts may set a minimum support amount even for very low-income obligors

Add-Ons: Childcare, Health Insurance, and Medical

Form 14 incorporates these additional expenses into the calculation:

• Work-related childcare: Added to the basic support amount (Line 3), shared proportionally by income
• Health insurance premiums: The child's portion of premiums is added and allocated by income share
• Uninsured medical/dental: Extraordinary medical expenses beyond routine care are typically shared in proportion to income
• Private school/special needs: May be addressed as a deviation factor if reasonable and necessary

Deviation from Guidelines (50% Limit)

Missouri permits deviation from the presumed amount only after finding the presumed amount is unjust or inappropriate:

• Maximum deviation: Generally limited to 50% above or below the presumed amount
• Written findings required: Courts must state the specific reasons for deviation
• Deviation factors include: Child's extraordinary needs, educational opportunities, financial resources of both parents, custody arrangements, and standard of living
• Voluntary reduction: A parent cannot unilaterally agree to pay less than the guideline amount without court approval

Common Calculation Mistakes

• Wrong overnight threshold: Credit starts at 36 nights, not at a lower number
• Missing the stepped table: Each overnight range has a specific percentage; don't interpolate
• Ignoring the 50% deviation cap: Even with agreement, deviations typically cannot exceed 50%
• Forgetting add-ons: Childcare and health insurance are added to the basic amount before allocation
• Using net instead of gross: Form 14 starts with gross income, not net

Modification and Duration

Missouri provides pathways to modify support:

• Substantial and continuing change: Required for modification; must be ongoing, not temporary
• Practical threshold: A 20% or greater change when recalculated is often considered substantial
• Material change examples: Job loss, significant income change, custody modification, child's special needs
• No automatic reviews: Either party must file a motion to modify

Duration: Support continues until age 18. If the child is still enrolled in secondary school at 18, support continues until completion or age 21, whichever comes first. For higher education, support may be extended to age 21 if the child is enrolled in a vocational or higher education program, provided the child began the program before age 21 and is making satisfactory progress.

Enforcement and Interest

Missouri provides robust enforcement tools:

• Interest on arrears: 1% per month (12% per year) simple interest on unpaid support under RSMo 454.520
• Income withholding: Mandatory in most cases; employers must comply within 7 days of receipt
• Tax refund intercepts: Federal and state refunds applied to arrears
• License suspension: Driver's, professional, and recreational licenses may be suspended
• Passport denial: When arrears exceed $2,500
• Credit bureau reporting: Arrears reported to credit agencies
• Contempt of court: Willful nonpayment may result in jail time

Key Takeaways

• Income Shares via Form 14: Presumed amount from schedule, allocated by income shares
• $30,000/month combined income cap: Court discretion applies above this threshold
• Overnight credit starts at 36 nights: Stepped percentages from 6% to 34% maximum
• Equal custody (181-183 nights): 34% credit; higher earner pays the difference
• Deviation limited to 50%: Written findings required for any deviation
• 1%/month interest: 12% annual simple interest on arrears
• Support to 21 for education: Extends beyond 18 if in secondary school or higher education

For more information about Missouri divorce processes, see our Missouri divorce timeline and filing checklist.