Wash. Rev. Code § 35.50.040
When the local improvement assessment is payable in installments, the enforcement of the lien of any installment shall not prevent the enforcement of the lien of any subsequent installment.
A city or town may by general ordinance provide that upon failure to pay any installment due the entire assessment shall become due and payable and the collection thereof enforced by foreclosure: PROVIDED, That the payment of all delinquent installments together with interest, penalty, and administrative costs at any time before entry of judgment in foreclosure shall extend the time of payment on the remainder of the assessments as if there had been no delinquency or foreclosure. Where foreclosure of two installments of the same assessment on any lot, tract, or parcel is sought, the city or town treasurer shall cause such lot, tract, or parcel to be dismissed from the action, if the installment first delinquent together with interest, penalty, administrative costs, and charges is paid at any time before sale.
RCW 35.50.040