Probate Code § 15300
CHAPTER 2. Restrictions on Voluntary and Involuntary Transfers
Except as provided in Sections 15304 to 15307, inclusive, if the trust instrument provides that a beneficiary’s interest in income is not subject to voluntary or involuntary transfer, the beneficiary’s interest in income under the trust may not be transferred and is not subject to enforcement of a money judgment until paid to the beneficiary.