(1) Except as otherwise provided in subsection (7) of RCW 26.09.070, the provisions of any decree respecting maintenance or support may be modified: (a) Only as to installments accruing subsequent to the petition for modification or motion for adjustment except motions to compel court-ordered adjustments, which shall be effective as of the first date specified in the decree for implementing the adjustment; and, (b) except as otherwise provided in subsections (5), (6), (9), and (10) of this section, only upon a showing of a substantial change of circumstances. The provisions as to property disposition may not be revoked or modified, unless the court finds the existence of conditions that justify the reopening of a judgment under the laws of this state.

     (2) Unless otherwise agreed in writing or expressly provided in the decree the obligation to pay future maintenance is terminated upon the death of either party or the remarriage of the party receiving maintenance or registration of a new domestic partnership of the party receiving maintenance.

     (3) Unless otherwise agreed in writing or expressly provided in the decree, provisions for the support of a child are terminated by emancipation of the child or by the death of the parent obligated to support the child.

     (4) Unless expressly provided by an order of the superior court or a court of comparable jurisdiction, the support provisions of the order are terminated upon the marriage or registration of a domestic partnership to each other of parties to a paternity order, or upon remarriage or registration of a domestic partnership to each other of parties to a decree of dissolution. The remaining provisions of the order, including provisions establishing paternity, remain in effect.

     (5) An order of child support may be modified one year or more after it has been entered without showing a substantial change of circumstances:

     (a) If the order in practice works a severe economic hardship on either party or the child;

     (b) If a party requests an adjustment in an order for child support which was based on guidelines which determined the amount of support according to the child's age, and the child is no longer in the age category on which the current support amount was based;

     (c) If a child is still in high school, upon a finding that there is a need to extend support beyond the eighteenth birthday to complete high school; or

     (d) To add an automatic adjustment of support provision consistent with RCW 26.09.100.

     (6) An order or decree entered prior to June 7, 1984, may be modified without showing a substantial change of circumstances if the requested modification is to:

     (a) Require health insurance coverage for a child named therein; or

     (b) Modify an existing order for health insurance coverage.

     (7) An obligor's voluntary unemployment or voluntary underemployment, by itself, is not a substantial change of circumstances.

     (8) The department of social and health services may file an action to modify an order of child support if public assistance money is being paid to or for the benefit of the child and the child support order is twenty-five percent or more below the appropriate child support amount set forth in the standard calculation as defined in RCW 26.19.011 and reasons for the deviation are not set forth in the findings of fact or order. The determination of twenty-five percent or more shall be based on the current income of the parties and the department shall not be required to show a substantial change of circumstances if the reasons for the deviations were not set forth in the findings of fact or order.

     (9)(a) All child support decrees may be adjusted once every twenty-four months based upon changes in the income of the parents without a showing of substantially changed circumstances. Either party may initiate the adjustment by filing a motion and child support worksheets.

     (b) A party may petition for modification in cases of substantially changed circumstances under subsection (1) of this section at any time. However, if relief is granted under subsection (1) of this section, twenty-four months must pass before a motion for an adjustment under (a) of this subsection may be filed.

     (c) If, pursuant to (a) of this subsection or subsection (10) of this section, the court adjusts or modifies a child support obligation by more than thirty percent and the change would cause significant hardship, the court may implement the change in two equal increments, one at the time of the entry of the order and the second six months from the entry of the order. Twenty-four months must pass following the second change before a motion for an adjustment under (a) of this subsection may be filed.

     (d) A parent who is receiving transfer payments who receives a wage or salary increase may not bring a modification action pursuant to subsection (1) of this section alleging that increase constitutes a substantial change of circumstances.

     (e) The department of social and health services may file an action at any time to modify an order of child support in cases of substantially changed circumstances if public assistance money is being paid to or for the benefit of the child. The determination of the existence of substantially changed circumstances by the department that lead to the filing of an action to modify the order of child support is not binding upon the court.

     (10) An order of child support may be adjusted twenty-four months from the date of the entry of the decree or the last adjustment or modification, whichever is later, based upon changes in the economic table or standards in chapter 26.19 RCW.

[2008 c 6 § 1017; 2002 c 199 § 1; 1997 c 58 § 910; 1992 c 229 § 2; 1991 sp.s. c 28 § 2; 1990 1st ex.s. c 2 § 2; 1989 c 416 § 3; 1988 c 275 § 17; 1987 c 430 § 1; 1973 1st ex.s. c 157 § 17.]

NOTES:

     Part headings not law -- Severability -- 2008 c 6: See RCW 26.60.900 and 26.60.901.

     Short title -- Part headings, captions, table of contents not law -- Exemptions and waivers from federal law -- Conflict with federal requirements -- Severability -- 1997 c 58: See RCW 74.08A.900 through 74.08A.904.

     Severability -- Effective date -- Captions not law -- 1991 sp.s. c 28: See notes following RCW 26.09.100.

     Effective dates -- Severability -- 1990 1st ex.s. c 2: See notes following RCW 26.09.100.

     Effective dates -- Severability -- 1988 c 275: See notes following RCW 26.19.001.

     Severability -- 1987 c 430: "If any provision of this act or its application to any person or circumstance is held invalid, the remainder of the act or the application of the provision to other persons or circumstances is not affected." [1987 c 430 § 4.]