42 CFR §440.150

1. (a)“ICF/IID services” means those items and services furnished in an intermediate care facility for Individuals with Intellectual Disabilities if the following conditions are met:
   1. (1)The facility fully meets the requirements for a State license to provide services that are above the level of room and board;
   2. (2)The primary purpose of the ICF/IID is to furnish health or rehabilitative services to persons with Intellectual Disability or persons with related conditions;
   3. (3)The ICF/IID meets the standards specified in subpart I of part 483 of this chapter.
   4. (4)The beneficiary with Intellectual Disability for whom payment is requested is receiving active treatment, as specified in § 483.440 of this chapter.
   5. (5)The ICF/IID has been certified to meet the requirements of subpart C of part 442 of this chapter, as evidenced by a valid agreement between the Medicaid agency and the facility for furnishing ICF/IID services and making payments for these services under the plan.
2. (b)ICF/IID services may be furnished in a distinct part of a facility other than an ICF/IID if the distinct part—
   1. (1)Meets all requirements for an ICF/IID, as specified in subpart I of part 483 of this chapter;
   2. (2)Is clearly an identifiable living unit, such as an entire ward, wing, floor or building;
   3. (3)Consists of all beds and related services in the unit;
   4. (4)Houses all beneficiaries for whom payment is being made for ICF/IID services; and
   5. (5)Is approved in writing by the survey agency.