How to collect unpaid child support in Montana

How unpaid support is collected, interest and license rules, and a free letter asking the agency to enforce.

Checked against official sources: Oct 25, 2026.

Short answer

Arrears means child support that is past due. Montana judgment interest is the bank prime rate (set each January 1) plus 3%, not compounded.

License suspension
A notice of intent to suspend a license can be issued when past-due support equals 6 months of payments or more.
Passport denial
Over $2,500 past due (federal law)

What the agency can do in Montana

Arrears means support that is past due. The child support agency can use these tools to collect it:

  • Income withholding
  • Federal and state tax refund offset
  • Federal administrative payment offset
  • Credit bureau reporting
  • Passport denial
  • Driver's, occupational and recreational (hunting/fishing) license suspension
  • Lottery winnings intercept ($600 and over)
  • Freezing and seizing bank accounts and other assets
  • Liens on real and titled personal property

Law: Mont. Code Ann. Title 40, ch. 5; 40-5-701 to 40-5-713

Ask the agency in writing to collect what is owed: Ask the agency to collect unpaid support

Interest on unpaid support in Montana

Montana judgment interest is the bank prime rate (set each January 1) plus 3%, not compounded. CSSD does not calculate interest; it collects interest on unpaid support only after the interest has been turned into a lump-sum judgment by an order.

Law: Mont. Code Ann. 25-9-205

Source: CSSD Enrollment Form, Terms and Conditions

Licenses in Montana

A notice of intent to suspend a license can be issued when past-due support equals 6 months of payments or more. The license is suspended 60 days after service unless the parent pays in full or agrees to a payment plan.

Law: Mont. Code Ann. 40-5-701(3), 40-5-702

Federal collection tools

  • Tax refunds. The federal government can take a federal tax refund to pay past-due child support. Law: 42 U.S.C. 664
  • Passports. A parent who owes more than $2,500 in past-due support can be refused a passport. Law: 42 U.S.C. 652(k)
  • Pay withholding limit. For support, up to 50% of take-home pay can be withheld if the parent supports another spouse or child, or 60% if not. It is 55% or 65% when support is more than 12 weeks behind. Law: 15 U.S.C. 1673(b)
  • Past-due support. Each unpaid payment becomes a judgment on the day it is due. It can't be lowered later, except back to the date the other parent got notice of a request to change the order. Law: 42 U.S.C. 666(a)(9)

Court action in Montana

You can ask the District Court to hold the other parent in contempt for not paying. The court self-help page has a 'Petition for Contempt of Court for Failure to Pay Support' packet.

In nearby states

What to do now in Montana

  1. Track what was paid

    A simple list of payments received and missed helps the agency.

  2. Ask the agency to enforce

    Ask for enforcement from Montana DPHHS Child Support Services Division (CSSD) (1-800-346-5437) · Apply online

  3. Share what you know

    Leads about income or address speed up collection.

  4. Get the numbers in writing

    Request a written statement of what is owed.

Where to get free help in Montana

Questions about unpaid support in Montana

What can the agency do about unpaid support in Montana?

Arrears means support that is past due. The child support agency can use these tools to collect it: Income withholding; Federal and state tax refund offset; Federal administrative payment offset; Credit bureau reporting; Passport denial; Driver's, occupational and recreational (hunting/fishing) license suspension; Lottery winnings intercept ($600 and over); Freezing and seizing bank accounts and other assets; Liens on real and titled personal property.

Can unpaid support cost a driver's license in Montana?

A notice of intent to suspend a license can be issued when past-due support equals 6 months of payments or more. The license is suspended 60 days after service unless the parent pays in full or agrees to a payment plan.

Can a parent go to jail for unpaid support in Montana?

You can ask the District Court to hold the other parent in contempt for not paying. The court self-help page has a 'Petition for Contempt of Court for Failure to Pay Support' packet.

Is there interest on unpaid child support in Montana?

Montana judgment interest is the bank prime rate (set each January 1) plus 3%, not compounded. CSSD does not calculate interest; it collects interest on unpaid support only after the interest has been turned into a lump-sum judgment by an order.

Related Montana pages

Sources

Sources

Last checked: Oct 25, 2026.

Federal sources