(a) Validity.--A spendthrift provision is valid only if it restrains both voluntary and involuntary transfer of a beneficiary's interest.
(b) Creation.--A trust instrument providing that the interest of a beneficiary is held subject to a "spendthrift trust," or words of similar import, is sufficient to restrain both voluntary and involuntary transfer of the beneficiary's interest.
(c) Effect.--A beneficiary may not transfer an interest in a trust in violation of a valid spendthrift provision. Except as otherwise provided in this subchapter, a creditor or assignee of the beneficiary of a spendthrift trust may not reach the interest or a distribution by the trustee before its receipt by the beneficiary.