Miss. Code Ann. § 91-8-601

The capacity required to create, amend, revoke, or add property to a revocable trust, or to direct the actions of the trustee of a revocable trust, is the same as that required to make a will. To be effective as a post-death disposition of property transferred during the transferor’s life or by the transferor’s will to a trust of which the transferor is the settlor or deemed to be the settlor, neither a revocable nor an irrevocable trust existing on or executed after July 1, 2014, has to be executed with the formalities of a will.