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Montana Child Support Calculator & Guidelines (2026)

Estimate Montana child support under Mont. Admin. R. 37.62 (Melson-variant) — Melson Formula model, current caps and percentages, with a step-by-step worked example.

This state uses a worksheet/table-based guideline that cannot be fully reproduced in a simplified tool. The range above is an approximation — use the official state calculator for the guideline figure. Official state calculator →

Estimate Your Child Support

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Montana Child Support Rules at a Glance

Guideline model Melson Formula
Income basis Net (after-tax) income
How it works Both parents’ incomes are combined, a basic obligation is taken from the state’s official schedule, and each parent pays in proportion to their share of combined income.
Statute / rule Mont. Admin. R. 37.62 (Melson-variant)
Parameters verified pending full verification (model and statute confirmed)

Worked Example: $5,000 + $3,000 Income, Two Children

  1. Paying parent’s monthly income: $5,000 - other parent’s: $3,000 - two children, primary custody.
  2. Simplified income shares estimate: combined income $8,000 x 24% (two children) = $1,920 basic obligation.
  3. Paying parent’s share: 62.5% of $1,920 = $1,200 - shown as a range of $1,020-$1,380 to reflect state schedule differences.
  4. For the exact figure use the official state calculator linked below - this state’s guideline uses its own obligation schedule.

Result: $1,020 - $1,380 per month (simplified range)

Montana Child Support FAQ

How is child support calculated in Montana?

Montana uses the Melson formula under Mont. Admin. R. 37.62 (Melson-variant) - a variant of income shares that first reserves a self-support allowance for each parent before allocating support. It requires the official worksheet for an accurate figure.

Does Montana use gross or net income for child support?

Montana calculates support on net (after-tax) income as defined in Mont. Admin. R. 37.62 (Melson-variant).

Can a Montana court order more or less than the guideline amount?

Yes. The guideline amount under Mont. Admin. R. 37.62 (Melson-variant) is presumptive, not absolute - courts may deviate with written findings for factors like extraordinary medical or educational needs, other children supported, or very high income beyond the guideline range.

How do I apply for or modify child support in Montana?

Apply through the Montana child support agency or the family court in your county. Existing orders can be modified on a substantial change in circumstances - typically a significant income change, job loss, or a change in custody. The official calculator/worksheet is linked on this page (dphhs.mt.gov).

Official Montana Resources

Related Calculators & States

About This Estimate

Estimate only — not legal advice. Based on Montana guidelines (Mont. Admin. R. 37.62 (Melson-variant)). Courts may deviate. For an official figure use the official Montana calculator.