Last verified: February 2026
A complete guide to Montana child support laws, including the uniform guidelines, how support is calculated, and your rights and obligations as a parent.
Montana child support laws require that support amounts be adequate and reasonable. The state uses uniform guidelines adopted by the Department of Public Health and Human Services, with each case determined based on its specific circumstances.
Quick Summary: Montana Child Support
- Calculation method: Montana Uniform Child Support Guidelines
- Key statute: Montana Code Annotated 40-4-204
- Age of termination: 18, or 19 if still in high school
- Review period: 36 months between reviews
- Medical support: Required in all orders
If after reading this you have further questions and would like a consultation, you can get a free case consultation from a local lawyer here.
How to apply for child support in Montana
The Montana Department of Public Health and Human Services (DPHHS) handles child support services, including:
- Locating parents
- Establishing paternity
- Establishing and modifying child support orders
- Establishing medical support orders
- Enforcing support obligations
To apply for services, visit your local Child Support Services office or call (800) 346-5437.
Key points to remember:
- Legal paternity must be determined before a support order can be issued
- Montana child support guidelines dictate the amount ordered
- Pay attention to timeframes for requesting hearings in your support notice
- All support orders in Montana include a provision for medical support
Establishing paternity in Montana
Montana child support guidelines require both parents to support their children, whether married or unmarried. Children have a right to know their parents and to learn about any inherited health conditions.
Paternity can be established through:
- Voluntary acknowledgment: Signing a paternity acknowledgment form
- Court adjudication: A judge determines paternity after reviewing evidence
- Genetic testing: DNA testing provides conclusive proof
- Presumed paternity: A child born during marriage or within 300 days after divorce, death, or annulment is presumed to be the husband’s child
Montana also maintains a Putative Father Registry to help locate parents. You can search the registry or register at DPHHS Vital Records.
How is child support calculated in Montana?
Under Montana Code Annotated 40-4-204, child support is calculated using the uniform guidelines adopted by DPHHS. The amount determined under the guidelines is presumed adequate and reasonable unless the court finds it would be unjust or inappropriate.
Factors considered
The court must consider all relevant factors under MCA 40-4-204, including:
- The financial resources of the child
- The financial resources of both parents
- The standard of living the child would have enjoyed if the marriage had not dissolved
- The physical and emotional condition of the child and educational and medical needs
- The age of the child
- The cost of day care
- Any existing parenting plan
- The needs of any other person the parent is legally obligated to support
Note that marital misconduct is NOT a factor in determining support amounts.
Calculation methods
Montana uses different formulas depending on custody arrangements:
- Sole custody: Considers both parents’ incomes, time spent with the child, and guideline factors
- Joint custody: Time spent with the child is the primary consideration; more time with the child typically means lower support obligations
Key calculation points
- Montana does not use the standard Income Shares Method or Percentage of Income Method found in other states
- The more parenting time you have, the lower your support obligation
- Extraordinary medical costs (braces, hospital visits, etc.) are mandatory deductions
- Care costs and general child-rearing costs are calculated separately
- Montana guidelines do not explicitly require college expense contributions, but such agreements can be made outside of court
Deviation from guidelines
If the court finds the guideline amount is unjust or inappropriate, it must:
- State its reasons for that finding
- Include the amount that would have been ordered under the guidelines
- Provide clear and convincing evidence supporting the deviation
How to modify child support in Montana
Montana law allows parents to request a review of existing orders 36 months after the order was established or last reviewed.
To request modification before 36 months, you must demonstrate a “significant and ongoing change in circumstances,” defined as:
- A change in the physical custody of the child
- An increase in daycare or medical expenses
- New children requiring support
- A 30% or greater change in income (increase or decrease)
Steps to modify support
- Contact the investigator assigned to your case
- Request a review packet from the investigator
- Submit the completed packet with supporting documentation
Important: If neither parent responds to a review notice, the court finalizes the order by default based on the terms in the notice.
Find all legal forms here or call 1-800-666-6899.
Key modification rules
- Either parent may request a modification
- A new spouse’s income is not considered when calculating modifications
- Stepparents are not obligated to support children from a previous relationship
Enforcement and penalties for non-payment
The Child Support Enforcement Division (CSED) within DPHHS enforces child support orders using federal and state remedies:
- Income withholding: The primary collection method; employers must withhold support from wages, bonuses, and salaries
- Credit bureau reporting: Delinquency affects credit scores, mortgages, loans, and employment
- Tax refund interception: Federal and state refunds may be seized
- License suspension: If arrears exceed six months, recreational, professional, or driver’s licenses may be suspended
- Passport denial: If arrears exceed $2,500, passports are denied or revoked
Contempt of court
Under Montana Code Annotated 40-5-601, if a parent fails to pay support, the receiving parent can petition the court to find the obligor in contempt.
Contempt penalties include:
- Up to 5 days incarceration in the county jail
- Up to 120 hours of community service
- Up to a $500 fine
However, a parent can avoid contempt charges by showing clear and convincing evidence of insufficient income to pay arrears or another reasonable excuse under the guidelines.
Statute of limitations
Under MCA 27-2-201(3), the statute of limitations for collecting past-due child support that accrued after October 1, 1993, is:
- 10 years from the termination of the support obligation, OR
- 10 years from entry of a lump-sum judgment for arrears, whichever is later
When does child support end in Montana?
Under Montana law, child support terminates when the child:
- Graduates from high school, OR
- Turns 18, but no later than 19
Support may continue past age 18 if the child has a mental or physical disability that prevents self-support.
If you are supporting multiple children, petition for modification when one reaches the age of majority to reduce your obligation.
Emancipation in Montana
Montana law allows minors to petition for emancipation. Requirements include:
- Must be at least 16 years old
- Must be financially independent
- Income must be from a legal source
Download emancipation petition forms here.
Termination of parental rights
Montana allows parents to voluntarily give up their parental rights to permit adoption. The child may also seek emancipation to end the parent-child legal relationship.
Either option requires court approval and a finding that the action serves the child’s best interests.
Frequently Asked Questions
How is child support calculated in Montana?
Montana uses uniform guidelines adopted by the Department of Public Health and Human Services. The calculation considers both parents’ incomes, parenting time, childcare costs, medical expenses, and other factors. More parenting time typically results in lower support obligations.
How often can I request a child support review in Montana?
You can request a review every 36 months. Earlier reviews are possible if there is a significant change in circumstances, such as a 30% income change, change in custody, or significant change in expenses.
At what age does child support end in Montana?
Child support ends when the child graduates from high school or turns 18, but no later than age 19. Support may continue indefinitely for children with physical or mental disabilities.
What happens if I do not pay child support in Montana?
Non-payment can result in wage garnishment, tax interception, credit damage, license suspension, and passport denial. Contempt of court charges carry up to 5 days in jail, 120 hours of community service, and $500 in fines.
Does Montana require medical support in child support orders?
Yes. Under MCA 40-4-204, every child support order must include a medical support provision addressing health insurance coverage for the child.
Does a stepparent have to pay child support in Montana?
No. Stepparents are not legally obligated to support children from their spouse’s previous relationship, and a new spouse’s income is not considered in child support calculations.
If you have additional questions, we recommend getting a free case consultation with a local lawyer.
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