Minn. Stat. § 501C.1203

If a trust forms part of a retirement plan created by and for the benefit of self-employed persons for the purpose of receiving their contributions and investing, accumulating, and distributing to the persons or their beneficiaries the corpus, profits, and earnings of the trust in accordance with the plan, the power of a person beneficially interested in the trust to sell, assign, or transfer that beneficial interest, to anticipate payments under the plan, or to terminate the trust, may be limited or withheld in accordance with the provisions of the plan, whether or not the person furnished consideration for the creation of the trust.