Cal. Elec. Code § 2208

(a) A person is presumed competent to vote regardless of the person’s conservatorship status. A person shall be deemed mentally incompetent, and therefore disqualified from voting, if, during the course of any of the proceedings set forth below, the court finds by clear and convincing evidence that the person cannot communicate, with or without reasonable accommodations, a desire to participate in the voting process, and any of the following apply:
1. (1) A conservator for the person or the person and estate is appointed pursuant to Division 4 (commencing with Section 1400) of the Probate Code.
2. (2) A conservator for the person or the person and estate is appointed pursuant to Chapter 3 (commencing with Section 5350) of Part 1 of Division 5 of the Welfare and Institutions Code.
3. (3) A conservator is appointed for the person pursuant to proceedings initiated under Section 5352.5 of the Welfare and Institutions Code, the person has been found not competent to stand trial, and the person’s trial or judgment has been suspended pursuant to Section 1370 of the Penal Code.
4. (4) A person has pleaded not guilty by reason of insanity, has been found to be not guilty pursuant to Section 1026 of the Penal Code, and is deemed to be gravely disabled at the time of judgment as defined in subparagraph (B) of paragraph (1) of subdivision (h) of Section 5008 of the Welfare and Institutions Code.
(b) If the proceeding under the Welfare and Institutions Code is heard by a jury, the jury shall unanimously find by clear and convincing evidence that the person cannot communicate, with or without reasonable accommodations, a desire to participate in the voting process before the person shall be disqualified from voting.
(c) If an order establishing a conservatorship is made and in connection with the order it is found by clear and convincing evidence that the person cannot communicate, with or without reasonable accommodations, a desire to participate in the voting process, the court shall provide notice to the Secretary of State pursuant to Section 2211.5.
(d) A person shall not be disqualified from voting pursuant to this section on the basis that the person does, or would need to do, any of the following to complete an affidavit of voter registration:
1. (1) Signs the affidavit of voter registration with a mark or a cross pursuant to subdivision (b) of Section 2150.
2. (2) Signs the affidavit of voter registration by means of a signature stamp pursuant to Section 354.5.
3. (3) Completes the affidavit of voter registration with the assistance of another person pursuant to subdivision (d) of Section 2150.
4. (4) Completes the affidavit of voter registration with reasonable accommodations.
(e) This section shall become operative on January 1, 2024.