20 C.F.R. § 416.907 Disability under a State plan.
Title 20 - Employees' Benefits
You will also be considered disabled for payment of supplemental security income benefits if— (a) You were found to be permanently and totally disabled as defined under a State plan approved under title XIV or XVI of the Social Security Act, as in effect for October 1972; (b) You received aid under the State plan because of your disability for the month of December 1973 and for at least one month before July 1973; and (c) You continue to be disabled as defined under the State plan.
Title 20: Employees' Benefits
PART 416—SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED
Subpart I—Determining Disability and Blindness
Definition of Disability
§ 416.907 Disability under a State plan.