Cal. Health & Safety Code § 7150.40

(a) Subject to subdivisions (b) and (c), and unless barred by Section 7150.30 or 7150.35, an anatomical gift of a decedent’s body or part for the purpose of transplantation, therapy, research, or education may be made by any member of the following classes of persons who is reasonably available, in the following order of priority:
1. (1) An agent of the decedent at the time of death who could have made an anatomical gift under subdivision (b) of Section 7150.15 immediately before the decedent’s death.
2. (2) The spouse or domestic partner of the decedent.
3. (3) Adult children of the decedent.
4. (4) Parents of the decedent.
5. (5) Adult siblings of the decedent.
6. (6) Adult grandchildren of the decedent.
7. (7) Grandparents of the decedent.
8. (8) An adult who exhibited special care and concern for the decedent during the decedent’s lifetime.
9. (9) The persons who were acting as the guardians or conservators of the person of the decedent at the time of death.
10. (10)
  1. (A) Any other person having the authority to dispose of the decedent’s body, including, but not limited to, a coroner, medical examiner, or hospital administrator, provided that reasonable effort has been made to locate and inform persons listed in paragraphs (1) to (9), inclusive, of their option to make, or object to making, an anatomical gift.
  2. (B) Except in the case where the useful life of the part does not permit, a reasonable effort shall be deemed to have been made when a search for the persons has been underway for at least 12 hours. The search shall include a check of local police missing persons records, examination of personal effects, and the questioning of any persons visiting the decedent before his or her death or in the hospital, accompanying the decedent’s body, or reporting the death, in order to obtain information that might lead to the location of any persons listed.
(b) If there is more than one member of a class listed in paragraph (1), (3), (4), (5), (6), (7), or (9) of subdivision (a) entitled to make an anatomical gift, an anatomical gift may be made by a member of the class unless that member or a person to which the gift may pass under Section 7150.50 knows of an objection by another member of the class. If an objection is known, the gift may be made only by a majority of the members of the class who are reasonably available.
(c) A person shall not make an anatomical gift if, at the time of the decedent’s death, a person in a prior class under subdivision (a) is reasonably available to make, or to object to the making of, an anatomical gift.