Incident-to Billing

By Tory McJunkin, MD, Paul Lynch, MD, Sagar Gondalia, & Ryan Tapscott, PhDpmnlogo

Dear Arizona Pain Specialists,

I have a small pain medicine practice, but we’re expanding fast. Our model for patient care relies heavily on the work of nurse practitioners and physician assistants. I recently read about a Medicare billing practice known as “incident-to” billing, but the guidelines seem complicated. What do you know about “incident-to” billing?

Thank you,

Incidentally Confused

Dear Incidentally Confused,

Congratulations on your success and growing practice! There is indeed a Medicare guideline known as incident-to billing. This is when a qualified mid-level provider (MLP –Physician Assistant, Nurse Practitioner, Clinical Nurse Specialist, Certified Nurse Midwife, Clinical Psychologist, Clinical Social Worker, Physical Therapist, Speech-Language Pathologist or Occupational Therapist) provides patient care, but bill the visit under the physician’s NPI (National Provider Identifier) rather than their own. Medicare pays mid-level providers (MLP) at 85% of the physician’s fee schedule. When billed incident-to, however, Medicare pays at 100% of the physician’s fee schedule because the visit is billed under the physician’s NPI.  The Medicare criteria for incident-to billing are not well understood by most physicians, but we will try to clear up any confusion.

According to Medicare, there are 9 criteria that must be met to qualify for incident-to billing:

  1. The patient treated by auxiliary staff must be an established patient of some physician and cannot be a new patient.
  2. The physician must have seen the patient first and initiated the plan of care that includes subsequent services by auxiliary staff.
  3. It is recommended that the physician inform the patient that a qualified practitioner will be caring for the patient under the physician’s direction and monitoring.
  4. Services provided and billed incident to must be for office or home services and ordered by a physician. Incident-to billing does not apply to hospital inpatient, CORF, or rehabilitation agency services. (Note, however, that incident-to billing does apply to outpatient hospital clinics and outpatient Skilled Nursing Facility (SNF) services.)
  5. The physician must be present on site, either in the office suite or in the patient’s home, during the time that the patient is seen and immediately available to provide assistance and direction throughout the time the qualified practitioner is performing services.
  6. The physician must remain actively involved in the patient’s care and must periodically see the patient for the ongoing disease or illness. It is also recommended that the physician review the qualified practitioner’s chart notes in order to monitor treatment progress.
  7. Incident-to rules do not apply if there is a new illness or problem for which the physician has not previously seen the patient and there is not an established plan of care.
  8. Billing must be done under the billing number of the physician who is actually “on-site” providing supervisory services rather than the physician who initiated and provides ongoing monitoring of the patient’s care.
  9. The qualified practitioner must be acting under the supervision of a physician and must be an employee, leased employee, or independent contractor of the physician, or of the legal entity that employs or contracts with the physician.[1]

Admittedly, this seems cumbersome and overwhelming. However, Arizona Pain Specialists has developed a set of easy questions to ask at each visit to accurately and quickly determine if a visit is eligible for incident-to billing status. Before revealing these questions, two terms must be defined: the Rendering Provider and the Billing Provider. The Rendering Provider is the practitioner who renders service. The Billing Provider is the practitioner under whom the service is billed. In a practice unconcerned with incident-to billing, these two would be the same. With incident-to billing, however, there are three possible situations:

  1. The billing AND rendering provider are both the Physician.
  2. The billing AND rendering provider are both the mid-level provider.
  3. The billing provider is the Physician and the rendering provider is the mid-level provider (This signifies that a visit is billed incident-to the physician)[2].

Arizona Pain Specialists has created a logic tree based on billing office visits that automatically determines rendering provider and billing provider (and implicitly incident-to billing). Because the office visit is always billed, regardless of other services performed during the visit, this logic tree is attached to the sections indicated on the superbill associated with the office visit codes (e.g., 99203-99205 & 99211-99215).

On the top of all clinic superbills is a section for both new patient office visits and established patient office visits. This creates an immediate dichotomy between the two and helps to simplify the process of determining the billing and rendering provider. The new patient section of the superbill definitively establishes that the visit cannot be billed incident-to (Figure 1). Either the MLP is both the billing and rendering provider, or, if the physician saw the patient, then the physician is both the billing and rendering provider. The visit cannot be billed incident-to the doctor because a plan of care hasn’t been established by a physician. Notice how this is explicitly indicated as a reminder to the provider while they complete the superbill.

Obviously, this is the easiest variant. Determining the rendering and billing provider for an established patient can be a little more complex as this is where incident-to billing is possible. Nevertheless, with a few easy questions built right into the superbill this can be deciphered without any headaches.

Notice in figure 2 that there are separate boxes for the Rendering and Billing provider, an indicator to the provider that it is possible for the two to differ (whereas with new patients the two must always be the same). If the patient was seen by a physician, the logic tree indicates that both the rendering and billing provider is the physician. If not, two possibilities remain: Either the MLP is both the rendering and billing provider, or the MLP is the rendering provider and the physician is the billing provider. There are three questions that determine this, which are listed below the initial queries. If, and only if, ALL three questions are answered “yes” the visit can be billed incident-to the MLP as the rendering provider and the physician as the billing provider. If ANY of the questions are answered no, then the MLP must be both the rendering and billing provider.

It is important to note that when billing incident-to the physician, the visit should be billed under the onsite supervising physician, even if this is not the same physician who established the plan of care. This scenario is further detailed in a single logic tree and flow chart that follows:

  • Is the patient new or established?
    • New
      • Was the patient seen and examined by a physician? If so, the physician is both billing and rendering provider. If not, the MLP is both billing and rendering provider.
      • Established
        • Was the patient seen and examined by a physician? If so, the physician is both billing and rendering provider. If not:
          • Was the current plan of care established by a physician?
          • Was the plan of care followed without change?
          • Is there an onsite supervising physician?
          • If any of these questions are answered NO: the billing and rendering provider are both the mid-level provider
          • If ALL of these questions are answered YES the rendering provider is the MLP and the billing provider is the onsite supervising physician.

These are the theory and the tools to determine if a visit should be billed incident-to. We have included several examples of hypothetical patients below to further illustrate how to use incident-to billing. These sample patients are not real people, and their names are entirely fictional.  Many insurance companies handle billing under MLPs differently than Medicare and some don’t recognize incident-to billing at all.  Before billing these insurance companies, you should make sure you understand how each insurance company wants you to bill with MLPs.

New Patients

  • Howahd Rorek arrived at our pain clinic with complaints of low back pain. He was seen initially by a nurse practitioner, but a physician was consulted and came into the room to perform an evaluation on the patient. The physician then determined the course of treatment for Howahd. In this case the physician saw the patient, and thus the rendering and billing provider should both be set to the physician.
  • Domineek Frankon was a new patient who had been suffering from severe pain in her left leg. There was no physician on the premises during Domineek’s first visit and she saw a physician assistant who determined the plan of care. The patient never saw a physician and so the physician assistant was both the rendering and billing provider.
  • Francysko D’Ankoniya was a new patient seeking treatment for foot and ankle pain in both of his extremities. He was seen by a nurse practitioner. There was an on-site physician and the NP briefly consulted the physician outside the exam room about Francysko’s plan of care. The physician did not, however, enter the room or perform an examination on the patient. Because the patient was not seen by the physician, the billing and rendering provider were both the NP.

Established Patients

  • Dagnee Taggert was a patient who had been on a continued plan of care for three months. She recently had a successful lumbar radiofrequency ablation procedure and was being seen in follow-up to that procedure. A physician saw Dagnee, so the physician is both the billing and rendering provider.
  • Jon Gahlt was seen for an initial visit two weeks ago and then came in for his first follow up appointment. He did not see a physician at his initial visit, and only saw the physician’s assistant at today’s visit. There was an onsite supervising physician present. The visit should be billed with the rendering and billing provider set to the MLP, because the patient’s plan of care was not established by a physician. Had the on-site physician seen the patient that day, and established a new or different plan of care, the visit would be billed with the physician as billing and rendering provider, and the patient would be eligible for incident-to billing for future visits.
  • Peetur Qiteeng met with a physician in his first office visit and has been working on slowly decreasing the amount of medication he is on. He came in for a follow up appointment to assess his progress. During this visit he saw a nurse practitioner. Additionally the onsite supervising physician was not the same as the original doctor that Peetur saw. Nonetheless, because there was a supervising physician present, and the patient’s plan of care was both established by a physician and the MLP followed that plan of care without change, the visit should be billed incident to the doctor: the MLP as the rendering provider and the onsite supervising physician as the billing provider.
  • Gayle Wyenend first met with a physician who established a plan of care. To help with his back pain, the plan involved double diagnostic medial branch blocks.  Gayle returned to the clinic and saw a nurse practitioner. Gayle had a fall and complained of new pain in his left arm. The physician was present, but didn’t visit or examine the patient about his new complaint.  Because there was a new pain complaint present and a new plan of care was established, the visit could not be billed incident-to. The billing and rendering provider were both the MLP.


Dr. McJunkin and Dr. Lynch founded Arizona Pain Specialists, a comprehensive pain management practice with three locations, seven pain physicians, ten midlevel providers, three chiropractors, on-site research, and behavioral therapy.  They teach nationally and are consultants for St. Jude Medical and Stryker Interventional Spine.   Through their partner company, Boost Medical, they provide practice management and consulting services to other pain doctors throughout the country. For more information, visit and


[1]Incident To Terminology and Billing by Qualified Practitioners – Revised” © 2010 Noridian Administrative Services, LLC posted on December 15,

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[2] These are the only three possible situations that allow for Incident To billing