Cal. Probate Code - PROB § 19330. Section 19330.
If proceedings are commenced under this part for the settlement of claims against the trust, and the time for filing claims has commenced, any action upon the liability of the surviving spouse under Chapter 3 (commencing with Section 13550) is barred to the same extent as provided for claims under this part, except as to the following:
(a)
Any creditor who commences judicial proceedings to enforce a claim and serves the surviving spouse with the complaint prior to the expiration of the time for filing claims.
(b)
Any creditor who has or who secures the surviving spouse’s acknowledgment in writing of the liability of the surviving spouse for the claim.
(c)
Any creditor who files a timely claim in the proceedings for the administration of the estate of the deceased spouse.