(a) Basic rule. The 50 States, the District of Columbia, and the Northern Mariana Islands must select one of the buy-in groups described in paragraph (b) in their buy-in agreements.

(b) Buy-in groups available—(1) Group 1. Cash Assistance and Deemed Recipients of Cash Assistance: This buy-in group includes all of the following:

(i) Individuals who receive SSI or SSP or both and are covered under the State's Medicaid state plan as categorically needy.

(ii) Individuals who under the Act or any other provision of Federal Law are treated, for Medicaid eligibility purposes, as though the individual was receiving SSI or SSP and are covered under the State's Medicaid state plan as categorically needy.

(iii) At State option, individuals whom the State must consider to be recipients of AFDC. Individuals a State would be required to include in electing this option would be, but not limited to, individuals eligible for Medicaid on the basis of section 1931(b) of the Act or their receipt of adoption assistance, foster care or guardianship care under Part E of title IV of the Act, in accordance with § 435.145 of this chapter.

(2) Group 2. Cash Assistance and Deemed Recipients of Cash Assistance and three Medicare Savings Program eligibility groups. This buy-in group includes both of the following:

(i) Group 1.

(ii) Individuals enrolled in the—

(A) Qualified Medicare Beneficiary eligibility group described in § 435.123 of this chapter;

(B) Specified Low-Income Beneficiary eligibility group described in § 435.124 of this chapter; and

(C) Qualifying Individual eligibility group described in § 435.125 of this chapter.

(3) Group 3. All Medicaid Eligibility Groups: This buy-in group includes all individuals eligible for Medicaid.