Montana Child Support Calculator

How Child Support Is Calculated in Montana

Montana determines child support using the formula defined in the Administrative Rules of Montana (ARM) Title 37, Chapter 62. The model first protects a "Personal Allowance" for each parent's basic subsistence, then funds the child's primary needs, and finally shares surplus income through a Standard of Living Adjustment.

Montana ARM Priority Steps

• Step 1: Personal Allowance (ARM 37.62.114). Each parent is allowed an amount equal to 1.3 times the monthly federal poverty guideline for a one-person household.
• Step 2: Primary Child Support Allowance (ARM 37.62.121). This is calculated as a percentage of the personal allowance: 30% for the first child, plus 20% for each of the second and third children, plus 10% for each additional child. Mandatory childcare costs are added.
• Step 3: Standard of Living Adjustment (ARM 37.62.128). Income remaining after the personal allowance and each parent's share of the primary allowance is shared with the child using the SOLA table: 14% for one child, 21% for two, 27% for three, 31% for four, and 35% for five.

Montana — Frequently Asked Questions

How is the personal allowance set?

Under ARM 37.62.114, the personal allowance equals 1.3 times the federal poverty guideline for a one-person household. Because it is tied to the poverty guideline, the protected amount is updated as the guideline changes each year.

What are the Montana SOLA rates?

The Standard of Living Adjustment factors in ARM 37.62.128 are 14% for one child, 21% for two children, 27% for three, 31% for four, and 35% for five children.

What is the minimum child support in Montana?

Montana applies a presumptive minimum support obligation. This estimator floors the result at $50 per month per child; specific low-income exceptions may apply.

How does parenting time affect the amount?

Montana applies a parenting-time adjustment when a child spends a significant number of overnights with the obligor. This estimate reflects a primary-custody arrangement and does not model shared-custody offsets.

Estimate only. This calculation is based on the Administrative Rules of Montana (ARM). For a binding order, consult the Montana CSSD or a qualified family law attorney.