SDCL § 55-18-20: Limitations on representation of settlor--Limitations on settlor's authority to bind beneficiary.

A settlor may be represented by a representative in amending, terminating, or revoking an inter vivos revocable trust only when the representative is:

(1) An agent under a written power of attorney when the settlor is incapacitated or not reasonably available and to the extent expressly authorized by the power of attorney with specific reference to the trust and expressly authorized by the terms of the governing instrument; or

(2) A conservator only to the extent authorized or approved by order of the court pursuant to § 29A-5-420 or equivalent provisions of another jurisdiction's laws.

In other respects, a settlor may be represented by a representative only pursuant to subdivisions 55-18-9(5), (11), (16), and (17) and pursuant to subdivision 55-18-9(1) to the extent authorized or approved by the court.

A settlor may not bind a beneficiary with respect to a trust termination pursuant to § 55-3-24 or 55-3-30 or a trust modification pursuant to § 55-3-24 or 55-3-30 where the ability to bind the beneficiary to the proposed trust modification would constitute a retained interest pursuant to 26 U.S.C. § 2036, as of January 1, 2017, or a revocable transfer pursuant to 26 U.S.C. § 2038 as of January 1, 2017.