When child support ends in Montana

The age support ends, the high school and disability rules, and what happens with orders from other states.

Checked against official sources: Oct 25, 2026.

Short answer

18, or graduation from high school if the child is still enrolled, whichever is later, but no later than the 19th birthday.

Usual end age
18
Law
Mont. Code Ann. 40-4-208(5)-(6)

The end age in Montana

18, or graduation from high school if the child is still enrolled, whichever is later, but no later than the 19th birthday

Law: Mont. Code Ann. 40-4-208(5)-(6)

Support can continue past 19 for a child with a disability who is financially dependent on the custodial parent, when that parent is the primary caregiver. Parents can also extend support by written agreement or the decree can say so. Support does not end when the paying parent dies.

Law: Mont. Code Ann. 40-4-208(5)-(7)

When does support end? Check your situation

Montana's rule: 18, or graduation from high school if the child is still enrolled, whichever is later, but no later than the 19th birthday

Law: Mont. Code Ann. 40-4-208(5)-(6)

Your own order may set a different end date, for example when the parents agreed to one. Read it.

Orders from another state

How long support lasts follows the law of the state that made the order, even if you move.

Law: 28 U.S.C. 1738B(h)(2)

A state must enforce another state's child support order. The state that made the order keeps the power to change it while a parent or the child still lives there.

Law: 28 U.S.C. 1738B(a), (d)

Arrears are still owed

Support that was due before it ended is still owed. Each unpaid payment became a judgment on the day it was due, and the agency can keep collecting it.

Law: 42 U.S.C. 666(a)(9)

In nearby states

Your next steps in Montana

  1. Look at the end date

    Some orders set their own end date.

  2. Check the rule

    The rule in Montana: 18, or graduation from high school if the child is still enrolled, whichever is later, but no later than the 19th birthday.

  3. Tell the agency

    The agency can end withholding when support ends: Montana DPHHS Child Support Services Division (CSSD) (1-800-346-5437) · Apply online

  4. Clear what is owed

    Arrears can still be collected after support ends.

Where to get free help in Montana

Questions about when support ends in Montana

When does child support end in Montana?

18, or graduation from high school if the child is still enrolled, whichever is later, but no later than the 19th birthday

Does child support continue while my child finishes high school in Montana?

18, or graduation from high school if the child is still enrolled, whichever is later, but no later than the 19th birthday

Can child support continue past the usual age in Montana?

Support can continue past 19 for a child with a disability who is financially dependent on the custodial parent, when that parent is the primary caregiver. Parents can also extend support by written agreement or the decree can say so. Support does not end when the paying parent dies.

Related Montana pages

Sources

Sources

Last checked: Oct 25, 2026.

Federal sources