Cal. Probate Code § 6341

If a testator’s will provides that devised property shall be paid or delivered or transferred to a custodian subject to the California Uniform Gifts to Minors Act or the California Uniform Transfers to Minors Act: (a) All of the provisions of the California Uniform Transfers to Minors Act, Part 9 (commencing with Section 3900) of Division 4, including, but not limited to, the definitions and the provisions concerning powers, rights, and immunities contained in that act, are applicable to the devise during the period prior to distribution of the property. (b) Unless the will clearly requires otherwise, if the person named as the beneficiary for whose benefit the custodial property is to be held attains the age at which the custodianship was to terminate prior to the order of distribution, the devise shall be deemed to be a direct devise to the person named as the beneficiary for whose benefit the custodial property was to be held. (c) The personal representative of the testator’s estate, upon entry of an order for distribution, shall make distribution pursuant to the order for distribution by transferring the devised property in the form and manner provided by the California Uniform Transfers to Minors Act. (d) If a vacancy in the custodianship exists prior to full distribution of the devised property by the personal representative, a successor custodian shall be appointed for any undistributed property in the manner provided by the California Uniform Transfers to Minors Act.