In general, property and debt orders in a Decree of Dissolution may not be modified after the case is finalized. Child support and maintenance may be modified until the order expires. Parenting Plans may only be modified by agreement, or after a special hearing to show that you have met the minimum threshold for a minor or major modification.
Maintenance may be modified upon the showing of a significant change in circumstances, and only as to installments that have not yet accrued. RCW 26.09.170(1).
In general, the genuine loss of a job is the most common reason to seek a modification.
Like child support, a petition to modify must be filed before the obligation for maintenance ends, or the court may lose jurisdiction to order the modification.