Montana Child Support Calculator
Calculate estimated child support using Montana's official guidelines
About Montana's Guidelines
Melson Formula variation
Note: Uses three-step calculation ensuring self-sufficiency
Key Information
- •Model: Melson Formula
- •Last Updated: January 15, 2024
Common Deviation Factors
Monthly Income
Melson Formula: Montana ensures each parent can meet their own basic needs (self-support reserve) before calculating child support. Income below the reserve threshold may result in a minimum support order.
Children & Custody
Additional Monthly Expenses
Estimates only — not legal advice. Consult a Montana family law attorney for official calculations.
Official Montana Court Forms
Download official court forms from the Montana judiciary website. These are free, legally valid forms for your family court case.
Child Support Forms
Official petitions & worksheets
Modification Forms
Request changes to orders
Financial Disclosure
Income & expense statements
These links go to official Montana court websites. Forms are free and provided by the state judiciary.
Montana Child Support Guidelines
Montana uses the Montana Child Support Guidelines (ARM 37.62.101-144) to determine child support obligations. The Melson Formula is an advanced version of the Income Shares model that first ensures each parent can meet their own basic needs through a self-support reserve before allocating child support. It also provides for a standard of living adjustment when income exceeds basic needs.
Montana has several distinctive features in its child support system. Montana is one of three states using the Melson Formula, which prioritizes self-sufficiency for both parents. Montana's version includes a "primary allowance" that covers basic necessities before support is calculated. The state has specific provisions for agricultural and seasonal workers common in Montana.
Montana bases calculations on net income — meaning income after mandatory deductions like taxes, Social Security, and Medicare. This gives a more accurate picture of each parent's take-home pay. The self-support reserve in Montana is $1,250/month, ensuring the paying parent retains enough income to cover basic living expenses.
How Montana Calculates Child Support
Montana follows a 6-step process under the Montana Child Support Guidelines (ARM 37.62.101-144):
- 1
Calculate each parent's net income after taxes and mandatory deductions
- 2
Step 1: Subtract the self-support reserve ($1,250) to determine available income
- 3
Step 2: From available income, calculate each parent's share of children's primary needs
- 4
Step 3: Apply the Standard of Living Adjustment (SOLA) to share surplus income
- 5
Total obligation = Step 2 amount + Step 3 amount
- 6
Apply shared parenting adjustment if 110+ overnights
Income Thresholds & Key Numbers in Montana
Self-Support Reserve
$1,250/mo
Shared Custody Threshold
110 nights/yr
30% of overnights
Income Basis
net
Sample Obligation Schedule
| Combined Monthly Income | 1 Child | 2 Children | 3 Children |
|---|---|---|---|
| $2,000 | $285 | $410 | $500 |
| $4,000 | $510 | $735 | $898 |
| $6,000 | $715 | $1,032 | $1,262 |
| $10,000 | $1,075 | $1,555 | $1,900 |
* Simplified schedule. Actual amounts may vary based on additional factors.
Custody Time Adjustments in Montana
Montana recognizes "Shared Parenting" when the non-custodial parent has the children for at least 110 overnights per year (approximately 30% of the time). When this threshold is met, the standard child support formula is adjusted to reflect the increased direct expenses borne by both parents.
Under the Melson Formula used in Montana, shared custody adjustments apply after the basic needs and standard of living calculations. The formula accounts for duplicated fixed costs (like maintaining two bedrooms) while reducing variable costs proportionally to the time spent with each parent.
Below 110 overnights, Montana generally treats the arrangement as a sole custody situation with standard visitation, and no custody time adjustment is applied to the child support calculation.
Frequently Asked Questions About Montana Child Support
Why does Montana use the Melson Formula?
How does Montana handle agricultural income?
How to Reduce Child Support Costs in Montana
While child support is determined by Montana's guidelines, there are legitimate ways to ensure your obligation is calculated fairly.
Increase Parenting Time
In Montana, more overnights with your children can reduce your support obligation. Document actual time spent and request a formal custody modification if needed.
Ensure Accurate Income Reporting
Both parents' incomes must be reported accurately. Verify that bonuses, overtime, and variable income are averaged correctly over the appropriate period.
Claim All Allowable Deductions
Montana allows deductions for items like mandatory retirement contributions, union dues, and health insurance premiums. Make sure all qualifying deductions are included.
Request a Modification When Eligible
If your income has decreased by 15-25% or more, you may qualify for a modification. File promptly — changes are typically not retroactive before the filing date.
Account for Other Children
If you have other children you're legally obligated to support, this can be factored into the calculation as a deduction in most states.
Review Healthcare & Childcare Costs
Ensure shared expenses like health insurance and childcare are divided proportionally. If costs have changed, update the court.
Key Facts About Child Support in Montana
Calculation Model
Melson Formula
Guidelines Source
State Statute
Review Frequency
Every 4 Years
Last Updated
January 15, 2024
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