No, a practice may not bill a nurse visit to Medicare in a Rural Health Clinic (RHC.)  

Rural Health Clinics are designated by Medicare. In some states, the RHC will also be designated as a RHC by Medicaid.  When so designated, the clinic is paid an all-inclusive rate for services performed on that day, at any level of service.

However, in order to bill Medicare and be paid the all inclusive rate, the service must meet the definition of a visit.  Here is how that is defined in the Medicare Claims Processing Manual:

The term “visit” is defined as a face-to-face encounter between the patient and a physician, physician assistant, nurse practitioner, nurse midwife, visiting nurse, clinical psychologist, or clinical social worker during which an RHC/FQHC service is rendered. (See the Medicare Benefit Policy Manual, Chapter 13, for definitions of these personnel. See also the Medicare Benefit Policy Manual, Chapter 13, for conditions of coverage for visiting nurse services).

The expense of the nurse is included in the all-inclusive rate, and in the cost report. It is not permitted to bill Medicare for a nurse visit in an RHC.