Washington Revised Code Title 11. Probate and Trust Law § 11.28.237. Notice of appointment as personal representative, pendency of probate--Proof by affidavit

(1) Within twenty days after appointment, the personal representative of the estate of a decedent shall cause written notice of his or her appointment and the pendency of said probate proceedings, to be served personally or by mail to each heir, legatee and devisee of the estate and each beneficiary or transferee of a nonprobate asset of the decedent whose names and addresses are known to him or her, and proof of such mailing or service shall be made by affidavit and filed in the cause. If a trust is a legatee or devisee of the estate or a beneficiary or transferee of a nonprobate asset of the decedent, then notice to the trustee is sufficient.

(2) If the personal representative does not otherwise give notice to creditors under chapter 11.40 RCW within thirty days after appointment, the personal representative shall cause written notice of his or her appointment and the pendency of the probate proceedings to be mailed to the state of Washington department of social and health services' office of financial recovery, and proof of the mailing shall be made by affidavit and filed in the cause.