Montana Divorce Guide

Child Support in Montana: How It Works

Montana sets child support with statewide guidelines that look at both parents' incomes. Here is the framework and where each piece is explained.

Written by

Misty Gaubatz, Partner, A&M Law

Licensed Montana attorney and co-founder of A&M Law. Over two decades in the practice of law focusing on family law, criminal defense, and DUI defense, with federal and state court experience and a Certificate in Mediation.

Montana Bar #122346+ years as an attorney, with over two decades working in the lawReviewed by Ashley HurlbertLast reviewed: August 4, 2026

Key Takeaways: Child Support in Montana: How It Works

In a dissolution, the court orders either or both parents to pay an amount reasonable or necessary for the child's support, without regard to marital misconduct (MCA § 40-4-204(1)).
The court must apply the Montana Child Support Guidelines in every case, including defaults and cases where the parents have agreed on a number (MCA § 40-4-204(3)(a)).
The guidelines amount is presumed adequate and reasonable. A court can vary from it only on clear and convincing evidence that it is unjust or inappropriate, and it must state its reasons.
Every child support order must include a medical support order (MCA § 40-4-204(4)).
Support is normally collected by income withholding unless the court makes a written exception (MCA § 40-4-204(5)).
Support generally ends at emancipation or high school graduation, whichever is later, but no later than the 19th birthday, with an exception for some children with disabilities (MCA § 40-4-208(5), (6)).

Child support in Montana is set by a statewide formula, not by what either parent thinks is fair. In a dissolution of marriage (the statutory term for divorce), the court orders either or both parents to pay an amount "reasonable or necessary" for the child's support, and it finds that amount by applying the Montana Child Support Guidelines (MCA § 40-4-204). This page is the overview for the child support section of our Montana Divorce Guide. Each topic below has its own page.

Both Parents Owe Support

Montana law puts the duty on both parents. A parent "shall give the child support and education suitable to the child's circumstances" (MCA § 40-6-211). In a dissolution, legal separation, or child support case, the court orders "either or both parents owing a duty of support" to pay, and it does so "without regard to marital misconduct" (MCA § 40-4-204(1)).

The guidelines are built on the same idea. They state that it is the first priority of parents to meet the needs of the child according to the parents' financial ability, and that a child's standard of living should not, to the degree possible, suffer because the parents live in separate households (ARM 37.62.101(2)).

What the Court Must Consider

The statute lists the factors a court weighs, and the guidelines are required to take the same factors into account (MCA §§ 40-4-204(2), 40-5-209(2)):

the financial resources of the child and of the parents;
the standard of living the child would have enjoyed had the marriage not been dissolved;
the child's physical and emotional condition and educational and medical needs;
the child's age and the cost of day care;
any parenting plan that is ordered or agreed to; and
the needs of any other person either parent is legally obligated to support.

The Guidelines Amount Is Presumed Correct

Whenever a court issues or modifies a child support order, it must use the guidelines. The statute says they "must be used in all cases," including a case decided by default and a case in which the parents have agreed on the amount (MCA § 40-4-204(3)(a)). The result is presumed to be an adequate and reasonable award.

A court may order a different amount only if it finds, by clear and convincing evidence, that applying the guidelines is unjust to the child or to a party, or inappropriate in that case. It then has to state its reasons and state the amount the guidelines would have produced (MCA § 40-4-204(3)(b)). If the court orders no support at all, it must say why (MCA § 40-4-204(3)(c)). The guidelines add that any variance must take the child's best interests into account (ARM 37.62.102(2)).

What Every Support Order Contains

A Montana child support order is more than a dollar figure. Under MCA § 40-4-204 it also has to include:

A medical support order covering health insurance and uncovered costs (subsection (4)).
Income withholding, or a written exception and a warning that withholding will follow a delinquency (subsection (5)).
A duty to keep contact, employer, and insurance information current with the court, which the court keeps confidential (subsection (6)).
A direction about who receives the payment, so that support follows the child if the child's residence changes by legal order (subsection (8)).

The guidelines calculate support on an annual basis, and it is paid in equal monthly installments (ARM 37.62.101(3)).

The Court and the Child Support Services Division

Two bodies set and change support in Montana. The district court does it in a dissolution or parenting case. The Child Support Services Division (CSSD) of the Department of Public Health and Human Services can also establish, review, modify, and enforce orders through an administrative process when it is providing services in a case (MCA §§ 40-4-204(7), 40-5-272). A parent who does not receive public assistance may apply for those services (MCA § 40-5-203(1)). Both use the same guidelines.

Where Each Topic Is Explained

Topic	What the page covers
How the amount is figured	Income, deductions, the personal allowance, the primary child support allowance, and each parent's share.
What counts as income	Wages, business income, benefits, imputed income, and what the guidelines leave out.
Parenting time	How the number of days with each parent changes the payment.
Health insurance and medical costs	The medical support order that must go with every child support order.
Changing an order	The standard for modification and the administrative review process.
When support ends	Emancipation, high school graduation, the 19th birthday limit, and children with disabilities.
Enforcement	Income withholding, liens, license suspension, tax refund offsets, and contempt.
Unpaid support	Arrears, interest, and how long a parent has to collect.
Self-employed parents	Business income, expenses, depreciation, and the records required.
Taxes	Which parent claims the child and what a decree can require.
Agreements between parents	Why an agreement for no support still has to pass the guidelines.

Child Support and the Parenting Plan

Support and parenting are decided together but are separate obligations. The parenting plan supplies the residential schedule the guidelines use to count days (ARM 37.62.124(1)). Montana's medical support statute states the principle directly: the duties to provide medical care, to pay child support, and to follow parenting arrangements "are independent of each other, and the failure or inability to provide one or more does not reduce one of the others" (MCA § 40-5-808(2)). A parent who is not receiving support cannot withhold parenting time for that reason, and a parent who is denied time is still required to pay. Our overview of parenting plans in Montana covers the parenting side, and our child support practice page describes how the firm helps.

If you and the other parent are able to work together, the firm's Cooperative Family Law process lets both of you sit down with a neutral and run the guidelines calculation from shared numbers. The result still goes to the court for approval.

This page explains Montana law in general as of the 2025 Montana Code Annotated and the current Montana Child Support Guidelines. It is not legal advice about your specific case.

Montana Divorce Guide Divorce How Child Support Is Calculated What Counts as Income for Child Support Parenting Time and Child Support Medical Support and Health Insurance

FAQ

Child Support in Montana: How It Works FAQ

Who pays child support in Montana?

Both parents owe a duty of support, and the statute lets the court order either or both to pay (MCA § 40-4-204(1)). The guidelines calculate an obligation for each parent and then net the two into a single transfer payment based on income and on where the child spends time. The law does not assign the payment by gender.

Does Montana use a formula for child support?

Yes. The court must apply the uniform child support guidelines adopted by the Department of Public Health and Human Services, found at ARM Title 37, chapter 62, subchapter 1. A guidelines worksheet has to be attached to the support order (ARM 37.62.148(3)). Our page on how child support is calculated walks through the steps.

Can a judge order a different amount than the guidelines?

Only with findings. The guidelines amount is presumed correct unless the court finds by clear and convincing evidence that applying it is unjust to the child or a party, or inappropriate in the case. The court must state its reasons and state what the guidelines amount would have been (MCA § 40-4-204(3)(a), (b)).

Does fault in the marriage affect child support?

No. The statute directs the court to set support without regard to marital misconduct (MCA § 40-4-204(1)). The calculation turns on income, the child's needs, and the parenting plan.

Do we need a court order if we agree on support?

If you are divorcing with children, the court has to address child support before it enters the decree, and the guidelines apply to agreed amounts too. An agreement on support is not binding on the court the way a property agreement is (MCA § 40-4-201(2)). See agreements on child support.

Questions About Child Support in Montana?

A&M Law is a Missoula family law firm. We can walk through how the guidelines apply to your family. Call 406-830-3060 for a confidential consultation.

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