U.S. Code Section 1396p.(d)(4)(A).
(4) This subsection shall not apply to any of the following trusts:
(A) A trust containing the assets of an individual under age 65 who is disabled (as defined in section 1382c(a)(3) of this title) and which is established for the benefit of such individual by the individual, a parent, grandparent, legal guardian of the individual, or a court if the State will receive all amounts remaining in the trust upon the death of such individual up to an amount equal to the total medical assistance paid on behalf of the individual under a State plan under this subchapter. Full text
42 U.S. Code § 1382c.
(a)(1) For purposes of this subchapter, the term “aged, blind, or disabled individual” means an individual who—
(A) is 65 years of age or older, is blind (as determined under paragraph (2)), or is disabled (as determined under paragraph (3)), and
(B) (i) is a resident of the United States, and is either (I) a citizen or (II) an alien lawfully admitted for permanent residence or otherwise permanently residing in the United States under color of law (including any alien who is lawfully present in the United States as a result of the application of the provisions of section 1182(d)(5) of title 8), or
(ii) is a child who is a citizen of the United States, and who is living with a parent of the child who is a member of the Armed Forces of the United States assigned to permanent duty ashore outside the United States.