42 CFR §433.148

1. (a)Deny or terminate eligibility for any applicant or beneficiary who—
   1. (1)Refuses to assign his own rights or those of any other individual for whom he can legally make an assignment; or
   2. (2)In the case of an applicant, does not attest to willingness to cooperate, and in the case of a beneficiary, refuses to cooperate in establishing the identity of a child's parents, obtaining medical child support and pursuing liable third parties, as required under § 433.147(a) unless cooperation has been waived;
2. (b)Provide Medicaid to any individual who—
   1. (1)Cannot legally assign his own rights; and
   2. (2)Would otherwise be eligible for Medicaid but for the refusal, by a person legally able to assign his rights, to assign his rights or to cooperate as required by this subpart; and
3. (c)In denying or terminating eligibility, comply with the notice and hearing requirements of part 431, subpart E of this subchapter.