Actually this is correct and incorrect. For Medicare and Medicaid the only first assists that can bill are physicians, PAs, NPs, CNS and CNM. RNFAs cannot bill Medicare and Medicaid.
"Medicare will make payment for an assistant-at-surgery when the procedure is covered for an assistant and one of the following situations exists:
The person reporting the service is a physician.
The person bears the designation of PA, NP, nurse midwife or CNS.
Physicians are prohibited from billing a Medicare beneficiary for assistant-at-surgery services for surgical procedures deemed non-covered for an assistant."
For other insurances its going to depend on the insurance contracts the hospital, physicians or RNFA has. Some of them follow Medicare guidelines others follow their own guidelines. There are 7-8 states that require Non-medicare insurance companies to reimburse RNFAs. YMMV