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Nonphysician Practitioner Billing

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The acronym NPP (nonphysician practitioner) is commonly used to describe a physician assistant (PA), nurse practitioner (NP), or clinical nurse specialist (CNS). An NPP is not a registered nurse, certified scrub technician, certified first assistant, certified registered nurse assistant, or medical assistant; Medicare does not credential auxiliary personnel.

Let’s start off by identifying the three types of billing for the NPP.‚Äč

Incident-To Billing

Medicare defines “incident-to” as a service provided by an NPP but billed by the physician using the physician’s National Provider Identifier (NPI). Incident-to billing does not apply to the hospital setting (e.g., critical care, inpatient, outpatient hospital, provider-based clinic). Only established patients with established problems can be billed under incident-to. If the established patient encounters a new or worsening problem, the patient encounter cannot be reported as incident-to. Incident-to does not apply to consultations or new patients in the office setting.

The advantage of incident-to billing is that the practice is reimbursed 100% of the Medicare Physician Fee Schedule (MPFS) allowable. If the NPP bills directly to Medicare, with his/her name and NPI on the claim form, then the payment is reduced to 85% of the MPFS allowable—a 15% reduction).

These services must meet all of the following six incident-to criteria:

1. The course of treatment is initiated by the physician, and the physician involvement reflects continuing active participation in and management of care.

  • NPPs cannot bill incident-to for evaluation of a new patient or established patient with a new problem or with a change in treatment or plan of care.
  • It is recommended that the physician review and cosign all NPP documentation for services billed incident-to.

2. The service provided is within the NPP’s stated scope of practice.

3. The service is furnished under the physician’s direct personal supervision.
  • The billing physician must be present in the office suite and immediately available to provide assistance and direction.
  • The billing physician does not have to be part of the patient’s primary care team.

4. The service is rendered without charge or included in the physician’s bill (i.e., NPP and physician services are not billed separately—only one charge is submitted).

5. The service is provided in the physician’s office or clinic.
  • Inpatient services cannot be billed incident-to, though they may be billed as a split/shared service.

6. The service is furnished by a physician or a clinician who qualifies as an employee of the physician.
  • Examples include employee, leased employee, independent contractor of physician, or legal entity that employs or contracts a physician.

Direct Billing

The NPP is reimbursed 85% of the MPFS allowable; therefore, the payment is reduced by 15%.

Assistant-at-surgery services are reimbursed at 13.6% of the MPFS allowable (85% of the 16% MPFS allowable for an assistant surgeon).

Direct billing under the NPP’s NPI number is allowed for critical care services.

Split/Shared Billing

Split/shared services are rendered by both the NPP and the physician and typically billed by the physician (but may be billed by the NPP). Split/shared cannot be reported for critical care services.

Only evaluation and management (E/M) services can be
split/shared. This means that both providers examined the
patient on the same calendar day.

1. Office: If the service is split/shared between the NPP and the physician and the service does not meet incident-to guidelines, then this service should be billed using the NPP’s NPI.

2. Hospital:
a. If the service is split/shared between the NPP and the physician, and both examined the patient and both documented their services, then this service should be billed using the physician’s NPI. (It may also be billed using the NPP’s NPI, in which case the 15% payment reduction will apply.)

b. If the service is split/shared between the NPP and the physician, and only the NPP examined the patient and documented the service, then this service should be 
billed using the NPP’s NPI.

c. Split/shared services cannot be reported for critical care services.

Critical Care
1. Qualified NPPs may provide critical care services (and report for payment under their NPI) when these services meet the above critical services definitions and requirements.
  • An NPP and a physician must be employed by the same entity for them to bill jointly.

2. Providers should note the following additional requirements:
  • The critical care services that NPPs provide must be within the scope of practice and licensure requirements for the state in which they practice and provide the services, and
  • NPPs must meet the collaboration, physician supervision, and billing requirements, and PAs must meet the general physician supervision requirements.

3. NPP time and physician time cannot be combined to calculate a primary critical care E/M service.
Example: An NPP is called urgently to the surgical intensive care unit for a patient in respiratory distress on extracorporeal membrane oxygenation. The NPP provides 40 minutes of critical care to stabilize the patient. The physician arrives, examines the patient, reviews the findings, and spends 18 minutes providing full attention to the patient.

Use code 99291 under the NPP name and NPI number or 99231-99233 under the physician’s name and NPI number, depending on the documentation. The physician may use the NPP’s documentation combined with his/her own to arrive at a level of service of 99231-99233. In this case, it is probably better to use the NPP’s critical care time for billing. 

NPPs may bill incident-to the physician when all criteria are met. Auxiliary personnel may also bill incident-to the NPP for nondiagnostic testing services, in which case Medicare will reimburse at the NPP rate (85% of the physician allowable). NPPs may examine a new patient or an established patient with a new problem (if state scope of practice allows) but must direct bill for these services; services to new patients and established patients with a new problem or change in plan of care by the NPP do not meet incidentto billing guidelines. The NPP may bill incident-to the supervising physician for services rendered to an established patient examined for an established problem when the NPP is carrying out the plan of care set by the physician.

Split/shared services can be reported in the office setting (if incident-to requirements are met) and in the hospital setting if both the physician and NPP examine the patient on the same date of service. The service can be reported under either the physician’s or NPP’s NPI number. If billed under the NPP’s NPI number, 85% of the physician allowable is paid. If billed under the physician’s NPI number, 100% of the allowable is paid.

Direct billing can be reported in the office, hospital, and critical care settings. When the NPP bills under his/ her NPI number 85% of the physician allowable is paid. Critical care services cannot be reported split/share.

Source: Centers for Medicare and Medicaid Services. Publication 100-4. Chapter 12. Washington, DC: Centers for Medicare and Medicaid Services; 2017.