How to Calculate Child Support Payments in Montana

How to Use the Montana Child Support Worksheet

Unlike many other states, Montana does not provide an official, online calculator for child support. But the state does provide Child Support Guidelines Worksheets that you can use to calculate your basic support obligation, based on the current Montana child support guidelines.

You'll need to have some basic information on hand before filling in the worksheet, including both parents' income, what your physical custody (parenting time) arrangements will be, and certain expenses for the child (including health insurance coverage and work-related child care). If you're still negotiating issues like custody and alimony, you might try multiple calculations under different scenarios.

Are Online Montana Child Support Calculators Accurate?

Unless a calculator is endorsed by the Montana Courts, watch out for websites with so-called child support calculators for Montana. Unfortunately, there's no guarantee that these other calculators are accurate and up-to-date. Montana updates its child support guidelines regularly, but you usually can't tell whether any of these other websites have kept up with the latest changes.

It's best to stick with the official state resources (in the link above) to calculate the amount of child support you may pay or receive. Be aware, however, that this will be an estimate. As explained below, the judge may order a different amount in your case.

When Child Support May Be Different Than the Guideline Calculation

Montana presumes that the amount calculated under the guidelines is appropriate, but you may argue that a different amount would be better in your situation. Whether you and the child's other parent have agreed on a support amount that departs from the guideline or a judge decides for you, the judge will have to find that using the amount calculated under the guidelines would be unjust or inappropriate, and that a different amount would be in the child's best interests. (Montana Child Support Guidelines, Rule 02 (2024).)

Learn more about how child support works in Montana, including factors judges must consider when deviating from the guidelines and what gets counted as income when calculating support.

How to Apply for Child Support in Montana

Typically, you'll apply for child support as part of the process of filing for divorce in Montana. You'll include your completed child support worksheet along with the other divorce papers.

If you aren't married to your child's other parent, you may get help with requesting support by applying for child support services from the Child Support Services Division (CSSD) in the Montana Department of Public Health and Human Services. If needed, the CSSD may also help with establishing the child's legal paternity or parentage and locating absent parents.

How to Collect Child Support in Montana

The Montana CSSD will collect and process all court-ordered child support payments.

If you're having trouble collecting support payments, the Montana CSSD can also help enforce court-ordered child support. Depending on how much the other parent owes, the agency has several ways of enforcing child support, including withholding support from paychecks, reporting the debt to credit bureaus, intercepting income tax refunds, seizing money from bank accounts, placing liens on property (so the delinquent parent can't sell it or borrow money before paying off the debt), and suspending the parent's driver's or other licenses.

How to Change the Amount of Child Support

Either parent may request a modification in the amount of child support in Montana. Under Montana law, a judge may modify a child support order if:

• both parents have agreed to the change in writing, or
• one of the parents has provided evidence demonstrating that there's been a change of circumstances that is continuing and is so significant that the existing order is "unconscionable."

(Mont. Code § 40-4-208 (2024).)

You may request a review of your current child support order from the Montana CSSD to see if you qualify for a modification. If it's been less than three years since the order was issued or last reviewed, you'll need to demonstrate that there's been a substantial change of circumstances, such as a 30% change in a parent's income or a custody change. When it's been more than three years, you don't need to show changed circumstances to request a review. The review process could take up to 180 days.

If the CSSD review shows that there should be a different amount of child support under the guidelines, the parents have the option of agreeing to the change. Otherwise, either parent may request an administrative hearing on the modification issue. (Mont. Code §§ 40-5-272, 40-5-277 (2024).)

You also have the option of filing a modification request directly with the court. But without CSSD assistance, you should consider speaking with a family lawyer.