Incident To Services

Incident to is defined as services or supplies that are furnished incident to a physician's professional services when the services or supplies are furnished as an integral, although incidental, part of the physician's personal professional services in the course of diagnosis or treatment of an injury or illness and services are performed in the physician's office or in the patient's home. To qualify for payment under the incident to rules, services must be part of the patient's normal course of treatment, during which a physician personally performed an initial service and remains actively involved in the ongoing course of treatment.

Access the below incident to related information from this page.


Medicare pays for services rendered by employees (including leased employees and independent contractors, hereafter referred to collectively as employees) of a physician or a physician directed clinic only when all 'incident to' criteria are met. Coverage is available for the services of such nonphysician personnel as nurses, technicians and therapists when furnished 'incident to' the professional services of a physician/nonphysician practitioner. Medicare also pays for services rendered by employees of a Clinical Psychologist (CP), Nurse Practitioner (NP), Certified Nurse Midwife (CNM) or Clinical Nurse Specialist (CNS) only when all 'incident to' criteria are met. Remember that 'incident services' supervised by non-physician practitioners are reimbursed at 85% of the Medicare Physician Fee Schedule (MPFS). The services of the employee are covered when:

  1. The services are rendered under the direct supervision of the physician, CP, NP CNM, CNS, or in the case of a physician directed clinic, the Physician Assistant (PA).
  2. The services are furnished as an integral, although incidental, part of the physician's, CP's, NP's, CNM's or CNS's professional services in the course of the diagnosis or treatment of an injury or illness.
  3. Billing 'incident to' the physician, the physician must initiate treatment and see the patient at a frequency that reflects his/her active involvement in the patient's case. This includes both new patients and established patients being seen for new problems. The claims are then billed under the physician's NPI.
  4. Billing 'incident to' the CP, NP, CNM, CNS or PA, the nonphysician practitioners may initiate treatment and see the patient at a frequency that reflects his/her active involvement in the patient's case. The claims are then billed under the nonphysician practitioner's NPI.

There must be a valid employment arrangement between the physician, CP, NP, CNM, CNS or physician directed clinic, and the employee. Since NPs, CNSs and PAs can enroll with Medicare Part B to receive their own PTAN number, services provided by these specialties would only be considered 'incident to' if all the above conditions are met. If all the above conditions are not met, the service is not truly 'incident to' and cannot be billed under the physician's NPI.

The physician/nonphysician practitioner cannot hire and supervise a professional whose scope of practice is outside the provider's own scope of practice as authorized under State law or whose professional qualifications exceed those of the "supervising" provider. For example, a CNM may not hire a psychologist and bill for that psychologist's services under the 'incident to' provision, since a psychologist's services are not integral to a CNM's personal professional services and are not regularly included in the CNM's bill.

A physician may also have the services of certain nonphysician practitioners covered as services 'incident to' a physician's professional services. These nonphysician practitioners, who are being licensed by the States under various programs to assist or act in the place of the physician, include for example Certified Registered Nurse Anesthetists (CRNAs), CP, Clinical Social Workers (CSWs), PAs, NPs and CNSs.

Services performed by these nonphysician practitioners 'incident to' a physician's professional services include not only services ordinarily rendered by a physician's office staff person (e.g. medical services such as taking blood pressure and temperatures, giving injections and changing dressings), but also the services ordinarily performed by the physician himself or herself such as minor surgery, setting casts or simple fractures, reading X-rays and other activities that involve evaluation or treatment of a patient's condition.

Note: Title 18, Section 1861 clearly states that the practice of medicine and all allied services are dependent on the rules and regulations within the state in which the individual practices. It is the responsibility of the physician/nonphysician practitioner to be in compliance with state regulations governing the licensing requirements of employees to provide specific services and limitations on the number of employees that can be adequately supervised.

Terminology Defined

  • Immediately Available: CMS has clarified that "immediately available" means "without delay" so Noridian considers "immediately available" to mean the supervising physician is in the office suite or patient's home, readily available and without delay, to assist and take over the care as necessary.
  • Office Suite: An "office suite" is limited to the dedicated area, or suite, designated by records of ownership, rent or other agreement with the owner, in which the supervising physician or practitioner maintains his/her practice or provides his/her services as part of a multi-specialty clinic.

Direct Supervision

Office Setting

Direct supervision in an office setting does not mean that the physician, CP, NP, CNM, CNS, or in the case of the physician directed clinic, the PA (hereafter referred to collectively as the physician/nonphysician practitioner) be physically present in the same room as his/her/clinic employee. However, they must be present in the office suite and immediately available to provide assistance and direction throughout the time the employee is performing the services.

  • In your office, qualifying 'incident to' services must be provided by a caregiver qualified to provide the service, whom you directly supervise, and who represents a direct financial expense to you (such as a W-2 or leased employee, or an independent contractor)
  • You do not have to be physically present in the treatment room while the service is being provided, but you must be present in the immediate office suite to render assistance if needed
  • If you are a solo practitioner, you must directly supervise the care
  • If you are in a group, any physician member of the group may be present in the office to supervise
    Hospital or SNF
  • For inpatient or outpatient hospital services and services to residents in a Part A covered stay in a SNF the unbundling provision (1862)(a)(14) provides that payment for all services are made to the hospital or SNF by a Medicare intermediary (except for certain professional services personally performed by physicians and other allied health professionals)
  • Incident to services are not separately billable to the carrier or payable under the physician fee schedule
    Offices in Institutions
  • In institutions including SNF, your office must be confined to a separately identifiable part of the facility and cannot be construed to extend throughout the entire facility
  • Your staff may provide service incident to your service in the office to outpatients, to patients who are not in a Medicare covered stay or in a Medicare certified part of a SNF
  • If your employee (or contractor) provides services outside of your 'office' area, these services would not qualify as 'incident to' unless you are physically present where the service is being provided
  • One exception is that certain chemotherapy 'incident to' services are excluded from the bundled SNF payments and may be separately billable to the carrier

Physician Directed Clinics

In clinics, particularly those that are departmentalized, direct personal physician/nonphysician practitioner supervision may be the responsibility of several physicians/nonphysician practitioners, as opposed to an individual attending physician/nonphysician practitioner. In this situation, medical management of all services provided in the clinic is assured. The physician/nonphysician practitioner ordering a particular service need not be the physician/nonphysician practitioner who is supervising the service. Therefore, services performed by the therapist and other aides are covered even though they are performed in another department of the clinic. The service would be billed under the NPI of the supervising physician/nonphysician practitioner.

Outside the Office

If auxiliary personnel perform services outside the office (e.g., in a patient's home or in an institution), Medicare covers their services as 'incident to' a physician's/nonphysician practitioner's service only if there is direct personal supervision by the physician/nonphysician practitioner. Services provided by auxiliary personnel in an institution (i.e., hospital, skilled nursing facility, nursing or convalescent home) present a special problem in determining whether direct physician/nonphysician practitioner supervision exists. The availability of the physician/nonphysician practitioner by telephone and the presence of the physician/nonphysician practitioner somewhere in the institution does not constitute direct supervision.

Certain services may be covered under the 'incident to' provision when provided in the setting by auxiliary personnel employed by the physician/nonphysician practitioner and working under his/her direct supervision. However, many of these same services may not be covered when they are provided to hospital patients or nursing facility residents because the services do not ordinarily require performance by a physician and they are typically provided by personnel who are not employed by the physician and/or under his/her supervision in the hospital or nursing facility settings. Services such as therapeutic injections, breathing treatments and chemotherapy administration fall into this category.

In Patients' Homes

  • In general, you must be present in the patient's home for the service to qualify as an 'incident to' service
  • Exceptions to this direct supervision requirement apply to homebound patients in medically underserved areas where there are no available home health services only for certain limited services found in Pub 100-02. Chapter 15 Section 60.4 (B)
  • In this instance, you need not be physically present in the home when the service is performed, although general supervision of the service is required
  • You must order the services, maintain contact with the nurse or other employee, and retain professional responsibility for the service
  • All other incident to requirements must be met
  • A second exception applies when the service at home is an individual or intermittent service performed by personnel meeting pertinent state requirements (e.g., nurse, technician, or physician extender), and is an integral part of the physician's services to the patient

Direct Personal Supervision

Direct personal supervision means that the physician/nonphysician practitioner is physically present at the patient's place of residence when the service is performed. Medicare covers services rendered to homebound patients provided by non-physician practitioners under direct personal supervision, when the following criteria is met:

  • The service is an integral part of the physician's/nonphysician practitioner's services to the patient;
  • The services are included in the physician directed clinic's, physician's/nonphysician practitioner's bill and the services represent an expense to the clinic or physician/nonphysician practitioner; and
  • The services are reasonable and necessary and not otherwise excluded from Medicare coverage.

This coverage is limited to the following services: injections, venipuncture, EKG's, therapeutic exercises, insertion and irrigation of a catheter, changing of catheters and collection of catheterized specimen, dressing changes, replacement and/or insertion of nasogastric tubes, removal of fecal impaction (including enemas), sputum collection for gram stain and culture, paraffin bath therapy for hands and/or feet for rheumatoid arthritis or osteoarthritis and teaching and training (for the care of colostomy and ileostomy, the care of a permanent tracheotomy, testing urine, care of the feet for diabetic patients and blood pressure monitoring).

Homebound Patient

  • The patient must be considered homebound.
  • The service must be performed under direct personal supervision.
  • The services must be included in the physician's/nonphysician practitioner's or physician directed clinic's bill.

Homebound is defined as individuals considered confined to their home but are not necessarily bed ridden. However, the condition of these patients should be such that there exists a normal inability to leave home and, as a result, leaving their home would require a considerable and taxing effort. If the patients do in fact leave the home, the patients may nevertheless be considered homebound if the absences from the home are infrequent or for periods of relatively short duration. Therefore, beneficiaries will be considered homebound if they have a condition due to an illness or injury which restricts the individuals' ability to leave their place of residence except with the use of special transportation, or the assistance of another person or if they have a condition which is such that leaving their home would further endanger the patients' health or condition.

Aged persons who do not often travel from their home because of feebleness and insecurity brought on by advanced age are not considered confined to their home. If the patients are not considered "homebound," Medicare cannot pay for the service(s).

'Homebound' must appear in Item 19 on the CMS-1500 claim form or the electronic equivalent.

Note: This coverage should not be considered as an alternative to home health benefits where there is a participating home health agency in the area which could provide the needed services.


Employment means that the auxiliary personnel are paid wages or salary by the physician/nonphysician practitioner practice and the individual is considered to be employed for Social Security and Federal and State income tax purposes (e.g., contributions and income taxes are withheld). PA may be employed as independent contractors (1099 withholding). To be considered an employee, the nonphysician performing the 'incident to' service may be a part-time, full-time, or a leased employee of the supervising physician/nonphysician practitioner, physician group practice, or of the legal entity that employs the physician (hereafter referred to collectively as the physician or other entity) who provides direct personal supervision (as described below).

A leased employee is a nonphysician working under a written employee leasing agreement, which provides that:

  • The nonphysician, although employed by the leasing company, provides services as the leased employee of the physician or other entity; and
  • The physician or other entity exercises control over all actions taken by the leased employee with regard to the rendering of medical services to the same extent as the physician or other entity would exercise such control if the leased employee were directly employed by the physician or other entity.


Services rendered 'incident to' a physician's service should be billed under the employing physician's NPI, or in the case of a physician directed clinic the supervising physician's NPI, and are reimbursed as if the physician performed the service (no modifier required). If the physician is non-participating, then the services can be billed as either assigned or non-assigned.

Services rendered 'incident to' a nonphysician practitioner's service should be billed under the employing practitioner's NPI, or in the case of a physician directed clinic the supervising practitioner's NPI, and are reimbursed as if the practitioner performed the service.

The following practitioners must accept assignment: PAs, NPs, CNSs, CP, CSWs, CRNAs, CNMs and Registered Dieticians. Since these practitioners must accept assignment, any services billed 'incident to' these practitioner must be billed as assigned.

Incident to billing is paid at 100% of the physician fee schedule, whereas the qualified practitioners billing under their own billing numbers are paid at 85% of the physician fee schedule. If service delivery does not meet all incident to criteria, but qualifies for billing by the practitioner, payment is made at 85% of physician fee schedule when billed by nonphysician practitioners or 100% of fee schedule when billed by therapists.

Situation Performed by Billing
Established patient with no new problems NPP If 'incident to' requirements have been met service may be billed under supervising physician's NPI
Established patient with new problem NPP (only) Must be billed under NPP's NPI
Established patient with new problem NPP and Physician May be billed under physician if "incident to" requirements have been met. Documentation must support a face-to-face occurred with physician (during the encounter) and that he/she has initiated course of treatment. Physician must sign his/her entry




Last Updated Dec 09 , 2023