The Patient Protection and Affordable Care Act of 2010 requires that physicians and other practitioners who prescribe or order services for Medicaid recipients, or who refer Medicaid recipients to other providers must be enrolled as participating Medicaid providers.
42 C.F.R.455.410 (b) states:
"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."