42 CFR § 455.410
Enrollment and screening of providers
June 11, 2020
(a) The State Medicaid agency must require all enrolled providers to be screened under to this subpart.
(b) The State Medicaid agency must require all ordering or referring physicians or other professionals providing services under the State plan or under a waiver of the plan to be enrolled as participating providers.
(c) The State Medicaid agency may rely on the results of the provider screening performed by any of the following:
(1) Medicare contractors.
(2) Medicaid agencies or Children's Health Insurance Programs of other States.