Montana child support calculator (2026 guidelines)
Montana guidelines effective February 1, 2026. Change state
For 2 children, with Parent A earning $60,000 and Parent B $40,000, Montana's guideline amount is $866 a month (Parent A pays Parent B).
Montana uses the Melson formula model; its current guidelines took effect February 1, 2026.
This is the guideline amount, not a court order.
Calculate your Montana guideline amount
Guideline child support
Choose your state and enter both incomes to see the guideline amount.
Montana child support at a glance
| Children | $30,000 | $50,000 | $75,000 | $100,000 |
|---|---|---|---|---|
| 1 child | $256 | $474 | $751 | $971 |
| 2 children | $256 | $678 | $1,102 | $1,440 |
| 3 children | $255 | $849 | $1,383 | $1,827 |
| 4 children | $280 | $928 | $1,544 | $2,040 |
| 5 children | $305 | $1,020 | $1,705 | $2,255 |
How Montana calculates child support
Montana uses a Melson-type formula on yearly amounts. Each parent keeps a personal allowance of $20,748. The children's primary allowance ($6,224 a year for one child) and their expenses are shared by the parents' incomes above the allowance; a standard of living adjustment then adds a share of each parent's remaining income.
Montana starts from total income, including the earned income credit and spousal support received, and subtracts income taxes, Social Security and Medicare, support ordered for other children, an allowance for other children at home and spousal support paid. Taxes here are estimated for a single filer. A parent with no income is treated as able to work full time at $10.85 an hour.
When the children spend more than 110 days a year with each parent, each parent's amount is reduced for the days above that number and the parent who owes more pays the difference.
Each parent keeps $20,748 a year. Each parent pays at least a minimum contribution: 12% of income after deductions, or a smaller percentage when that income is at or below the personal allowance.
Child care, the children's health insurance and their recurring medical costs above $250 a child a year are added to the children's needs and shared by income; the parent who pays them gets credit. Child care is first reduced by the federal dependent care credit when the parent who claims the children pays it.
Support ordered for other children is subtracted from income, and so is an allowance of half the primary allowance for other children living with the parent without an order.
There is no income cap. The standard of living adjustment is 14% of a parent's income available for it with one child, rising to 47% with eight or more children.
Every worksheet amount is rounded to the nearest dollar and the shares of income to two decimal places. Each child's yearly amount is rounded to the dollar, divided by twelve and rounded again; the monthly payment is the total for all the children.
Parenting time in Montana
When the children spend more than 110 days a year with each parent, each parent's amount is reduced for the days above that number and the parent who owes more pays the difference.
| Overnights with Parent A | Guideline amount | Who pays |
|---|---|---|
| 0 | $866 a month | Parent A pays Parent B |
| 52 | $866 a month | Parent A pays Parent B |
| 104 | $866 a month | Parent A pays Parent B |
| 128 | $674 a month | Parent A pays Parent B |
| 182 (about equal) | $100 a month | Parent A pays Parent B |
Low and high incomes in Montana
For 2 children with Parent B earning $40,000, the guideline amount is about $134 a month when Parent A earns $20,000 a year and about $3,214 a month when Parent A earns $250,000.
Each parent keeps $20,748 a year. Each parent pays at least a minimum contribution: 12% of income after deductions, or a smaller percentage when that income is at or below the personal allowance.
There is no income cap. The standard of living adjustment is 14% of a parent's income available for it with one child, rising to 47% with eight or more children.
Child support by number of children in Montana
- 1 child$598 a month
- 2 children$866 a month
- 3 children$1,089 a month
- 4 children$1,200 a month
- 5 children$1,320 a month
Parent A earns $60,000, Parent B $40,000; the children live mostly with Parent B.
Official sources and verification
- Law: MCA 40-4-204, 40-5-209, 40-6-116; Admin. R. Mont. 37.62.101–37.62.148
- Montana child support guidelines
- Montana Child Support Guidelines Worksheets A–E
- Montana DPHHS Child Support Services Division (CSSD)
- Changing a Montana child support order
Guidelines effective February 1, 2026. Verified against the official Montana sources on October 7, 2026. How we calculate →
Frequently asked questions
How is child support calculated in Montana?
Montana uses a Melson-type formula on yearly amounts. Each parent keeps a personal allowance of $20,748. The children's primary allowance ($6,224 a year for one child) and their expenses are shared by the parents' incomes above the allowance; a standard of living adjustment then adds a share of each parent's remaining income. Montana starts from total income, including the earned income credit and spousal support received, and subtracts income taxes, Social Security and Medicare, support ordered for other children, an allowance for other children at home and spousal support paid. Taxes here are estimated for a single filer. A parent with no income is treated as able to work full time at $10.85 an hour.
What is the child support for one child in Montana on $50,000?
If Parent A earns $50,000 a year, Parent B earns $40,000 and the child lives mostly with Parent B, Montana's guideline amount for one child is about $474 a month (Parent A pays Parent B). Courts can deviate from the guideline amount.
Does 50/50 custody mean no child support in Montana?
Not necessarily. With about equal parenting time, 2 children, Parent A earning $60,000 and Parent B $40,000, the guideline amount is about $100 a month (Parent A pays Parent B). When the children spend more than 110 days a year with each parent, each parent's amount is reduced for the days above that number and the parent who owes more pays the difference.
What is the minimum child support in Montana?
Each parent keeps $20,748 a year. Each parent pays at least a minimum contribution: 12% of income after deductions, or a smaller percentage when that income is at or below the personal allowance.
When does child support end in Montana?
In Montana, support ends when the child is emancipated (adulthood is 18) or graduates from high school if still enrolled, whichever is later, but no later than the 19th birthday, unless a written agreement or the decree extends it. Support for a child with a disability who is financially dependent on the custodial parent, the primary caregiver, is not ended by age alone.