How to Change a Parenting Plan in Washington

The standard for a major change

Except in the situations listed in the statute, the court may not modify a parenting plan or custody decree unless it finds, based on facts that have arisen since the prior plan or that were unknown to the court when it was entered, that a substantial change has occurred in the circumstances of the child or the nonmoving party, and that the modification is in the child’s best interest and necessary to serve the child’s best interests (RCW 26.09.260(1)). A parent’s military duties are not, by themselves, a substantial change justifying a permanent modification.

Even then, the court keeps the residential schedule in the existing plan unless (RCW 26.09.260(2)):

1. The parents agree to the modification;
2. The child has been integrated into the petitioner’s family with the other parent’s consent, in substantial deviation from the plan;
3. The child’s present environment is detrimental to the child’s physical, mental, or emotional health, and the harm likely to be caused by a change of environment is outweighed by the advantage of a change to the child; or
4. The court has found the nonmoving parent in contempt at least twice within three years for failing to comply with the residential time provisions, or that parent has been convicted of custodial interference in the first or second degree.

A conviction for custodial interference in the first or second degree is itself a substantial change of circumstances (RCW 26.09.260(3)).

Minor changes to the schedule

The court may adjust the residential schedule on a showing of a substantial change in circumstances of either parent or the child, and without the grounds in subsection (2), if the change is minor, does not change the home where the child lives the majority of the time, and (RCW 26.09.260(5)):

• does not exceed 24 full days in a calendar year;
• is based on a change of residence of the parent with whom the child does not live the majority of the time, or on an involuntary change in a parent’s work schedule that makes the residential schedule impractical to follow; or
• does not result in a schedule exceeding 90 overnights per year in total, where the court finds the plan does not provide reasonable time with the parent who has less time and that more time is in the child’s best interests. This third ground has limits: a party who already received a modification under it within 24 months must meet the subsection (2) grounds, and a parent whose time is limited under RCW 26.09.191 or 26.09.192, or who has not completed required evaluations, treatment, or classes, faces added conditions (RCW 26.09.260(5)(c), (7), and (9)).

Relief under subsection (5) cannot be the sole basis for adjusting or modifying child support.

Other kinds of changes

• Restricting contact. The court may reduce or restrict contact between the child and the parent with whom the child does not live a majority of the time, using the criteria in RCW 26.09.191 and 26.09.192 (RCW 26.09.260(4)).
• Time not used. If the parent with less time voluntarily fails to exercise residential time for one year or longer, the court may adjust the plan on proper motion, not counting time missed because of military duties (RCW 26.09.260(8)).
• Nonresidential terms. Decision-making, dispute resolution, and other nonresidential parts of a plan can be adjusted on a showing of a substantial change of circumstances of either parent or a child, if the adjustment is in the child’s best interest (RCW 26.09.260(10)).
• Relocation. A modification tied to a proposed move follows the relocation statutes and does not require a separate adequate cause hearing while the relocation request is pending (RCW 26.09.260(6)). See the relocation guide.

What you file

1. The summons and petition. The Summons: Notice about Petition to Change a Parenting Plan or Custody Order, FL Modify 600 (revised 09/2026) and the Petition to Change a Parenting Plan or Other Custody Order, FL Modify 601 (revised 07/2025). The petition has separate sections for a major change, a minor change, restrictions, and other changes, each tied to a subsection of RCW 26.09.260. If the current order came from a different county or state, the form tells you to attach or file a certified copy.
2. A supporting affidavit. A party seeking to modify a parenting plan must submit an affidavit setting out the facts supporting the change and give the other parties notice and a copy (RCW 26.09.270). In Washington a declaration under penalty of perjury can be used in place of an affidavit; see the declarations guide.
3. A proposed parenting plan, filed and served with the petition. The responding party files and serves one with the response (RCW 26.09.181(1)(b)).

If the order you want to change was entered in a divorce, legal separation, or invalidity case, you can file where the children now live, in the court that entered the order, or in the county where the parent or other person with care, custody, or control of the children lives (RCW 26.09.280). The statewide form explains that if you file under the same case number as the current order, the person listed as Petitioner in that order stays Petitioner even if the other parent is now asking for the change.

Adequate cause comes first

The other parties may file opposing affidavits, and the court must deny the request unless it finds that the affidavits establish adequate cause for hearing it. If they do, the court sets a hearing on an order to show cause why the change should not be granted (RCW 26.09.270). Either side can ask for that decision with the Motion for Adequate Cause Decision, FL Modify 603 (revised 01/2022), and the court rules on the Order on Adequate Cause to Change a Parenting/Custody Order, FL Modify 604 (revised 01/2022). If adequate cause is found, the case moves to a full hearing or trial. If not, the petition is dismissed. The motion form notes that the court may not allow testimony at the motion hearing, so the written declarations carry the case at this stage.

The other parent responds on the Response to Petition to Change a Parenting Plan or Custody Order, FL Modify 602 (revised 10/2023).

Child support and temporary orders

If your requested change would switch the parent the children live with most of the time, or substantially change time with the parent who pays support, the petition lets you ask the court to set or change child support too. The form warns that if the parenting plan is not changed, that support request may be denied, and points to the separate child support modification forms for other reasons. See the child support guide.

Temporary orders while a modification is pending are requested with the Motion for Temporary Family Law Order, FL Modify 623, which the form says is for non-emergency requests after notice to the other party. See the hearings guide, and the emergency relief guide for urgent situations.

Primary sources

Laws, rules and forms change. Check the current version at the source before you file.

• RCW 26.09.260, modification of parenting plan
• RCW 26.09.270, affidavits and adequate cause
• RCW 26.09.280, venue for modification and enforcement
• RCW 26.09.181, proposed parenting plans
• RCW 26.09.191, limitations in parenting plans
• Summons, FL Modify 600
• Petition to Change a Parenting Plan or Other Custody Order, FL Modify 601
• Response to Petition, FL Modify 602
• Motion for Adequate Cause Decision, FL Modify 603
• Order on Adequate Cause, FL Modify 604
• Motion for Temporary Family Law Order, FL Modify 623