Cal. Probate Code § 6600

(a) Subject to subdivision (b), for the purposes of this chapter, “decedent’s estate” means all the decedent’s personal property, wherever located, and all the decedent’s real property located in this state. (b) For the purposes of this chapter: (1) Any property or interest or lien thereon which, at the time of the decedent’s death, was held by the decedent as a joint tenant, or in which the decedent had a life or other interest terminable upon the decedent’s death, shall be excluded in determining the estate of the decedent or its value. (2) A multiple-party account to which the decedent was a party at the time of the decedent’s death shall be excluded in determining the estate of the decedent or its value, whether or not all or a portion of the sums on deposit are community property, to the extent that the sums on deposit belong after the death of the decedent to a surviving party, P.O.D. payee, or beneficiary. As used in this paragraph, the terms “multiple-party account,” “party,” “P.O.D. payee,” and “beneficiary” have the meanings given those terms in Article 2 (commencing with Section 5120) of Chapter 1 of Part 2 of Division 5.