HERITAGE FINANCIAL CORPORATION DEFERRED COMPENSATION PLAN PARTICIPATION AGREEMENT - ADDENDUM

This Participation Agreement Addendum (“Addendum”) is hereby entered into by and between HERITAGE FINANCIAL CORPORATION (the “Company”) and BRIAN L. VANCE, an employee of the Company (the “Participant,” and together with the Company, the “Parties”).

In consideration of the foregoing and the mutual promises and covenants of the parties hereto set forth in this Addendum, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto, intending to be legally bound, hereby expressly covenant and agree as follows:

Section 1.Distribution of Company Contribution Account. Notwithstanding anything contained in the Agreement to the contrary, for Company Contributions credited to the Participant’s Company Contribution Account with respect to Plan Year 2017 and each Plan Year thereafter (unless subsequently modified), in the event of distribution of the Participant’s Company Contribution Account due to the Participant’s attainment of age 65 or the Participant’s Separation from Service other than due to the Participant’s Disability or death, such distribution shall be paid (select one):

(a)    [ ] 24 equal monthly installments

(b)    [X] 60 equal monthly installments

(c)    Notwithstanding the foregoing, if such Separation from Service occurs within 24 months following a Change in Control, such distribution shall be in a lump sum.

Section 2.    Entire Agreement. This Addendum, in addition to the Participation Agreement and the Plan, constitutes the entire agreement between the Parties concerning the subject matter hereof, and supersedes all prior negotiations, undertakings, agreements, and arrangements with respect thereto, whether written or oral.

IN WITNESS WHEREOF, the Company and the Participant have duly executed this Addendum as of the date set forth below.