Child Support Modification - Preparation Worksheet - Washington

WASHINGTON CHILD SUPPORT MODIFICATION PREPARATION WORKSHEET

DO NOT FILE THIS WORKSHEET. Transfer verified facts to the current mandatory Washington Courts form for the selected route. Confirm the edition and local requirements when filing.

1. Select the Correct Route

Do not combine the petition and adjustment routes.

Petition to modify

Use current FL Modify 501 with FL Modify 500 and the required worksheets when the selected ground calls for a petition. Potential routes under current RCW 26.09.170 and the mandatory form include:

• ☐ substantially changed circumstances at any time;
• ☐ at least one year has passed and the order causes severe economic hardship;
• ☐ at least one year has passed and support must extend beyond age 18 to complete high school;
• ☐ at least one year has passed and an automatic-adjustment provision is requested;
• ☐ another route shown on the current mandatory petition applies: [ROUTE AND FACTS].

Motion to adjust

• ☐ At least 24 months have passed from the later of the current order or last adjustment or modification.
• ☐ The request is based on changed qualifying income.
• ☐ The request is based on changes in the chapter 26.19 economic table or standards.
• ☐ Current FL Modify 521, Motion to Adjust Child Support Order, is the correct route after review.

RCW 26.09.170(9) uses a motion plus child-support worksheets for the 24-month adjustment. Do not label that route a petition ground or assume that 24 months alone changes the order.

Selected route and reason: [____________________________________________________________]

2. Existing Order, Case, and Jurisdiction

Use the jurisdiction and venue questions in current FL Modify 501. Do not infer jurisdiction from a parent’s Washington address or a child’s residence without completing the order-state, party-location, registration, consent, and personal-jurisdiction analysis required by the actual facts.

3. Children and Current Terms

Requested subjects:

• ☐ monthly transfer payment;
• ☐ end date or dependent-adult-child support;
• ☐ postsecondary support addressed or reserved in the existing order;
• ☐ health insurance or uncovered health costs;
• ☐ daycare, education, long-distance transportation, or other child expenses;
• ☐ tax-related provisions, after current federal and state review;
• ☐ incarceration-abatement language or another specialized route;
• ☐ other: [________________________________].

4. Ground and Evidence Register

For each requested change, identify the exact route, facts arising after the operative order, and evidence.

For a substantial-change petition, explain the change without converting voluntary unemployment or voluntary underemployment, by itself, into an automatic ground.

For a one-year route, identify the specific hardship, high-school, or automatic-adjustment ground rather than stating only that one year elapsed.

For a 24-month adjustment, identify the income or schedule change and use the motion route if it is the only basis.

5. Current Financial Record and WSCSS Calculation

Current RCW 26.19.071(2) requires the preceding two years of tax returns, current paystubs, and other sufficient verification for income or deductions not shown there.

Use the current 2026 Washington State Child Support Schedule and current worksheets. Record:

• Standard calculation: $[________]
• Requested transfer payment: $[________]
• Deviation requested: ☐ No ☐ Yes
• Deviation facts, calculation, and requested findings: [________________________________]
• Worksheet version and completion date: [________________________________]

Do not use the former template’s fixed 50-percent wage-withholding claim, 12-percent compounded-interest claim, or income-percentage liability-cap metadata as support-calculation rules.

6. Requested Start Date and Relief

The current statute limits ordinary modification to installments accruing after the petition or adjustment motion, subject to the exceptions stated in the statute. The mandatory petition asks the filer to select and support a requested start date; the court decides the order.

Requested start date: [__/__/____]

Basis and calculation of any overpayment, underpayment, or credit request: [________________________________]

Requested order:

• ☐ set the current-law transfer payment;
• ☐ enter written findings supporting the calculation and any deviation;
• ☐ address health coverage and child expenses shown in the calculation;
• ☐ address the support end date or another properly supported subject;
• ☐ address arrears or enforcement only through a separately reviewed request;
• ☐ request fees or costs without stating an automatic prevailing-party entitlement;
• ☐ other relief and authority: [________________________________].

This worksheet creates no automatic withholding, garnishment, lien, license suspension, contempt, incarceration, interest, fee award, injunction, indemnity, liability cap, arbitration term, jury waiver, or electronic-original rule.

7. Mandatory Forms and Filing Packet

Confirm every edition on the current Washington Courts form page.

• ☐ FL Modify 500 — Summons: Notice about Petition to Modify Child Support Order (09/2025)
• ☐ FL Modify 501 — Petition to Modify Child Support (01/2022)
• ☐ Current WSCSS Schedule and Worksheets (06/2026)
• ☐ FL All Family 001 — Confidential Information (01/2026)
• ☐ FL All Family 002 — Attachment to Confidential Information, if needed
• ☐ FL All Family 011 — Sealed Financial Source Documents cover sheet (06/2026)
• ☐ FL All Family 131 — Financial Declaration (06/2026)
• ☐ Current proof-of-service form for the authorized service method
• ☐ FL Modify 502 — Response, for the responding party
• ☐ FL Modify 510 — Final Order and Findings on Petition to Modify
• ☐ FL All Family 130 — Child Support Order (01/2026)
• ☐ Local cover sheet, hearing form, filing fee or waiver, proposed order, and other county requirements

If the 24-month adjustment route is selected, replace the petition forms above with the current Adjust Child Support Order packet, including FL Modify 521 and its related forms.

8. Service and Response Checklist

Under current RCW 26.09.175:

• ☐ The summons, prescribed petition, and worksheets will be served together.
• ☐ If this is the first action filed in Washington, personal service will be used.
• ☐ If the decree was entered in Washington, the selected route is personal service or a form of mail requiring a return receipt.
• ☐ Proof of service will be filed.
• ☐ Any required service on the Attorney General or designated county prosecutor has been evaluated.
• ☐ The responding party’s answer and worksheets deadline is calculated from actual service: 20 days ordinarily or 60 days if served out of state.
• ☐ Local filing, scheduling, and hearing procedure are confirmed.

Do not use a generic certificate stating that first-class mail or email necessarily completes initial service. Email service requires a separately valid agreement or authority.

9. Declaration and Confidential Information

Use the declaration and signature block in the current mandatory form. Do not cite repealed RCW 9A.72.085 or substitute a custom verification.

File financial, medical, and other protected records using the current sealed cover sheets and General Rule 22 procedure identified by the mandatory form and local court.

10. Final Review and Future-Law Gate

• ☐ The petition or motion route matches the asserted ground.
• ☐ Jurisdiction and venue are supported by the current form’s facts.
• ☐ The existing order and every relevant later order are attached or available as required.
• ☐ All requested changes have dates, evidence, and calculations.
• ☐ Current WSCSS worksheets are complete and filed under penalty of perjury.
• ☐ Requested relief is prospective unless a specific current-law exception supports another date.
• ☐ Local superior-court rules and forms have been checked.
• ☐ The filing uses current mandatory forms, not this worksheet.

The official RCW page publishes a future version of RCW 26.09.170 effective April 1, 2027. Recheck the statute, schedule, and mandatory forms before any filing on or after that date.

Official Sources

• RCW 26.09.170
• RCW 26.09.175
• RCW 26.19.035
• RCW 26.19.071
• Washington Courts modification forms