Parents in Montana can agree on child support terms, including a low amount or none, but the agreement does not decide the matter. The court must still apply the child support guidelines, and it may approve an amount that differs from the guidelines result only if it finds the variance justified and says why (MCA § 40-4-204(3)). The reason is that support is owed for the child's benefit, and the law does not treat it as the parents' own to trade away. This page is part of our Montana Divorce Guide.
The Guidelines Apply to Agreements Too
The statute is explicit. The guidelines "must be used in all cases, including cases in which the order is entered upon the default of a party and those in which the parties have entered into an agreement regarding the support amount" (MCA § 40-4-204(3)(a)). The guidelines repeat the point: they apply to "contested, non-contested and default proceedings" (ARM 37.62.101(4)).
So even in a fully agreed divorce, a completed guidelines worksheet goes to the court, and a copy must be attached to the support order (ARM 37.62.148(3)). The worksheet shows the judge what the presumptive amount is. The agreement is then measured against it.
Why the Court Is Not Bound by a Support Agreement
Montana encourages spouses to settle. A written separation agreement's terms on property and maintenance are binding on the court unless it finds them unconscionable. The statute carves out one category: the terms "providing for the support, parenting, and parental contact with children" (MCA § 40-4-201(2)). On those subjects the court makes its own decision.
The underlying duty explains the carve-out. A parent "shall give the child support and education suitable to the child's circumstances" (MCA § 40-6-211), and the guidelines describe meeting the child's needs as the parents' "first priority" (ARM 37.62.101(2)). The obligation runs to the child. Two parents can settle what they owe each other. They have less room to settle what each of them owes their child.
What a Variance Requires
The guidelines amount is presumed adequate and reasonable. A court may depart from it only on clear and convincing evidence that applying the guidelines "is unjust to the child or to any of the parties or that it is inappropriate in that particular case" (MCA § 40-4-204(3)(a)). When parents have agreed to an amount that varies from the guidelines, "similar reasons must also be stated," along with the amount the guidelines would have produced (MCA § 40-4-204(3)(b)).
The guidelines spell out what an agreement itself must contain before support can vary on the basis of a stipulation:
| Requirement | What the rule says | Rule |
|---|---|---|
| In writing and voluntary | The agreement is in writing and executed by the parties free of coercion. | ARM 37.62.102(5)(a) |
| Specific justification | It contains specific justification as to why applying the guidelines is unjust or inappropriate. | ARM 37.62.102(5)(b) |
| Guidelines amount stated | It states the amount of support that would have been appropriate under the guidelines without the variance. | ARM 37.62.102(5)(c) |
| Approved | It has been approved by the court or in an administrative proceeding. | ARM 37.62.102(5)(d) |
Any variance "must take into account the best interests of the child" (ARM 37.62.102(2)). And where a variance rests on a condition or on a parent doing something, the order must provide that when those circumstances end, "the support immediately reverts to the amount which would have been ordered under the guidelines without the variance" (ARM 37.62.102(6)).
If the Agreement Is for No Support at All
A zero order is the largest possible variance, and the statute addresses it separately: "If the court does not order a parent owing a duty of support to a child to pay any amount for the child's support, the court shall state its reasons for not ordering child support" (MCA § 40-4-204(3)(c)).
The guidelines also lean against zero. They call for a specific minimum contribution when a parent's income is low or the calculated obligation is under 12% of income after deductions, and that minimum can be rebutted only with an appropriate finding on the record (ARM 37.62.126). Whether a particular judge will approve an agreed order of no support depends on the reasons given and the facts. No one can promise that result.
Why a Waiver May Not Hold Later
Even an approved agreement is not permanent. A decree may limit later modification of some agreed terms, but not terms concerning the support of the children (MCA § 40-4-201(6)). Child support stays open to modification under MCA § 40-4-208, and where the Child Support Services Division is providing services it may review the order under MCA § 40-5-272.
Three practical consequences follow:
- Either parent can later ask for a guidelines-based order if the legal standard for modification is met. See modifying child support.
- If a parent receives public assistance for the child, support rights may be assigned to the State, which is not a party to the parents' private understanding.
- An unapproved side deal to pay less than an existing order does not stop arrears from building at the ordered amount. See unpaid child support and interest.
Trading support for something else, such as a larger share of property or less parenting time, runs into the same wall. Property terms generally cannot be reopened later, while support can, so a parent who gives up property in exchange for a support waiver may later find the support term reopened while the property term stands. And the duties of support and of following the parenting plan are independent of each other (MCA § 40-5-808(2)).
How to Reach an Agreement That Works
Parents are free to agree on support. The agreement simply has to be built on the worksheet. Exchange complete income information, run the guidelines, and start from that figure. If you both believe a different amount is right for your child, write down the specific reasons, state the guidelines amount, and present both to the court. Medical support has to be addressed either way (MCA § 40-4-204(4)).
Parents who want to work this out together can do so in mediation or through the firm's Cooperative Family Law process, in which the firm serves as a neutral for both spouses and each remains free to consult a separate lawyer. See also marital settlement agreements, agreeing on everything before you file, and our child support overview.
One caution. If you are being pressured or threatened into giving up support, that is not an agreement "free of coercion." Anyone in danger should call 911, and the National Domestic Violence Hotline is 1-800-799-7233. Our Montana Domestic Violence Guide has more.
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.