Montana Child Support
Estimate for Montana
Montana uses the Melson Formula model.
Montana Child Support Worksheet — Planning Estimate
Paying parent income: $5,000.00/mo · Other parent: $4,000.00/mo · Overnights: 0/yr · Child care: $0.00/mo · Health ins.: $0.00/mo · Children: 2
This is an informal planning estimate, not a court worksheet and not legal advice. Confirm the current guideline with the state child-support agency or a licensed family-law attorney.
View calculation breakdown
| Self-support reserve (each parent) | $1,729 |
|---|---|
| POVC reserve (each parent) | $865 |
| Obligor adjusted income | $2,406 |
| Primary support pool (30% of adjusted) | $1,144 |
| Obligor primary support | $722 |
| Standard-of-living adjustment (obligor share) | 336.84% |
| Estimated monthly support | $1,059 |
Estimated monthly support by number of children
Typical amounts in Montana
| Scenario | Obligor income/mo | Other parent | Est. monthly support |
|---|---|---|---|
| Lower earner | $2,500 | $4,000/mo | $111/mo |
| Typical case | $5,500 | $4,000/mo | $1,431/mo |
| Higher earner | $9,000 | $4,000/mo | $2,971/mo |
Montana uses the melson model on net income. Your numbers will differ — run the calculator above with your own inputs. Estimates are educational, not a court order.
§ How Montana calculates support
Montana uses the Modified Melson Formula (ARM 37.62), one of three U.S. states. Each parent keeps a personal (self-support) allowance of $20,748/year (~$1,729/month, 1.3x the one-person poverty line), the child's primary support allowance is funded (30% of the personal allowance for one child, scaling with more children), and a Standard of Living Adjustment (SOLA) of 14%/21%/27%/31%/35% shares remaining income. Deviation requires clear-and-convincing evidence.
Content verified against official sources on 2026-08-09.
✦ How to open or modify a case in Montana
- Determine each parent's gross monthly income from all sources.
- Subtract taxes, FICA, and allowed deductions to get net available income.
- Subtract each parent's personal allowance ($1,729/month eff. 2/2026).
- Combine remaining income and compute the primary child support allowance (e.g., $519/mo for 1 child), split by income share.
- Apply the SOLA percentage (14% for 1 child, up to 35% for 5+) to income left after the allowance and primary support.
- Add the child's health insurance and childcare; allocate by income share using Form CS 404.2.
◈ Illustrative examples
Scenario: Parent A gross $5,000, Parent B gross $3,000; personal allowance $1,729 each. A available = $3,271, B = $1,271; combined $4,542.
Walk-through: Primary allowance $518.67/mo: A 72% = $373.44, B 28% = $145.23. SOLA income = $4,542 - $518.67 = $4,023.33; 14% = $563.27 split 72/28 = $405.55 / $157.72. Noncustodial B total ~$303/month plus add-ons.
Takeaway: Montana's formula protects parental subsistence first, then the child's primary need, then shares prosperity via SOLA.
? Frequently asked questions
↗ Official policy & agency links
Sources verified: https://rules.mt.gov/ · https://dphhs.mt.gov/cssd · https://recordinglaw.com/us-laws/united-states-child-support-laws/montana-child-support-laws/ · https://observed.org/child-support-guidelines-in-montana
How Montana calculates support
Montana uses the Melson Formula.