California Code, Probate Code - PROB § 5040

(a) Except as provided in subdivision (b), a nonprobate transfer to the transferor's former spouse, in an instrument executed by the transferor before or during the marriage or registered domestic partnership, fails if, at the time of the transferor's death, the former spouse is not the transferor's surviving spouse as defined in Section 78, as a result of the dissolution or annulment of the marriage or termination of registered domestic partnership.  A judgment of legal separation that does not terminate the status of spouses is not a dissolution for purposes of this section.

(b) Subdivision (a) does not cause a nonprobate transfer to fail in any of the following cases:

(c) Where a nonprobate transfer fails by operation of this section, the instrument making the nonprobate transfer shall be treated as it would if the former spouse failed to survive the transferor.

(d) Nothing in this section affects the rights of a subsequent purchaser or encumbrancer for value in good faith who relies on the apparent failure of a nonprobate transfer under this section or who lacks knowledge of the failure of a nonprobate transfer under this section.

(e) As used in this section, “nonprobate transfer” means a provision, other than a provision of a life insurance policy, of either of the following types: