Child Support Past 18 in Washington: High School Graduation and Age Limits
In Washington, child support ends at emancipation, the 18th birthday, unless the decree or a written agreement extends it. A court can extend it for a child still in high school, and arrears stay owed.
What is the child support age limit in Washington?
Unless otherwise agreed in writing or expressly provided in the decree, provisions for the support of a child terminate on emancipation of the child (RCW 26.09.170(3)). Washington courts treat emancipation as the 18th birthday, the age of majority, while noting that the obligation rests on dependency, not minority (Court of Appeals).
Can Washington support run past 18 for high school?
Yes. One year or more after the order is entered, it may be modified without a substantial change if a child is still in high school and there is a need to extend support past the 18th birthday to complete high school (26.09.170(8)(b)). Many orders already say support continues until high school ends; read yours.
| Child born (graduating in June of the year they turn 18) | Turns 18 | Support can run to | Turns 19 |
|---|---|---|---|
| March 15, 2012 | March 15, 2030 | June 30, 2030 | March 15, 2031 |
| August 31, 2011 | August 31, 2029 | August 31, 2029 | August 31, 2030 |
| November 2, 2015 | November 2, 2033 | November 2, 2033 | November 2, 2034 |
Try your own dates in the Washington child support end date calculator.
Where does the Washington age 19 come from?
Washington administrative orders commonly provide support until the child turns 18 or graduates from secondary school, whichever is later, if the child is a full-time student and has not reached 19, as quoted in a Court of Appeals opinion about an agreed settlement (OP869132). The statute itself sets no age 19 cap, so your order controls.
Does a Washington written agreement matter?
Yes. The statute lets parties agree in writing to something other than termination at emancipation, and a court of appeals treated an agreed administrative order extending support for a student under 19 as such an agreement (26.09.170(3); Court of Appeals).
What if my order says nothing about high school?
Then support ends at emancipation (26.09.170(3)); you may ask for an extension by modification, one year or more after entry, if the child is still in high school (26.09.170(8)(b)). Ask before the 18th birthday.
Does the child have to live with the parent?
The statute we read for the high school extension does not say; it asks for a finding of need to complete high school (26.09.170(8)(b)). Bring proof of enrollment and residence anyway.
Can a Washington court extend support past 19?
The statute section we read does not set an age cap for the high school extension, but state orders commonly stop at 19; ask the court how far it will go (26.09.170(8)(b)).
What does the court weigh for an extension?
The statute asks for a finding that there is a need to extend support beyond the eighteenth birthday to complete high school (26.09.170(8)(b)); bring the school’s enrollment and expected graduation letters.
Do I have to do anything for the order to end?
The statute ends the obligation at emancipation unless extended, but withholding and the agency’s records need a court or agency step. Send proof of the birthday or graduation and ask in writing to end withholding.
Do arrears end when child support ends?
No. Unpaid support remains a judgment enforceable for 10 years after the youngest child turns 18 (6.17.020(2)). See the Washington child support arrears calculator and how long arrears last.
Frequently asked questions
Does child support end at 18 in Washington?
Yes, unless the order or a written agreement extends it, for example for high school.
How long can Washington high school support last?
As the order provides; state orders commonly stop at graduation or 19.
Can Washington modify support to extend it for high school?
Yes, one year or more after entry, if a child is still in high school.
Is the Washington age of 19 in the statute?
No. It comes from order language; the statute does not set a 19-year cap.
Do arrears end when Washington support ends?
No. Installments already owed stay owed.
Official sources
- RCW 26.09.170: termination and extension
- RCW 26.19.090: postsecondary educational support
- RCW 6.17.020: duration of judgments
- Childers v. Childers: support based on dependency, not minority
- Washington Court of Appeals, Division One: emancipation and written agreements
A local family law attorney can review your situation — many offer a free consultation.
This is general information, not legal advice. It is based on the cited Washington statutes, rules and court opinions, and every case turns on its own facts. Confirm how the law applies to your situation with a licensed Washington attorney.