Incident-To Billing: The Conditions and the Record

Incident to billing in one paragraph and four conditions

Incident to billing is a payment rule, not a visit type. Section 1861(s)(2)(A) of the Social Security Act lets Medicare pay for a service furnished under a physician’s number when auxiliary personnel, including a nurse practitioner or physician assistant, perform it as an integral part of the physician’s own care. The conditions sit in 42 CFR 410.26 and in the Medicare Benefit Policy Manual, Chapter 15, Section 60.

Billed this way, the visit is paid as though the physician performed it: 100 percent of the Medicare Physician Fee Schedule. Billed under the practitioner’s own national provider identifier, the same visit pays 85 percent. CMS states both rates on its Incident To Services and Supplies page. On a visit that allows $120, the spread is $18.

Medicare’s rule does not travel to other payers. Incident to billing is a Medicare construct, and many commercial and Medicare Advantage plans do not recognize it at all. A contract that prices a nurse practitioner visit at 85 percent of the physician rate will not pay the physician rate because a note records supervision. Read the fee schedule attachment before billing that way.

The service has to sit inside the physician’s plan of care

The manual’s first condition is also its definition. Section 60.1 says a service or supply is incident to a physician’s professional services when it is an integral, although incidental, part of the physician’s personal professional services in the course of diagnosis or treatment of an injury or illness.

The plan also has to stay alive. Section 60.2 requires subsequent services by the physician of a frequency that reflects the physician’s continuing active participation in and management of the course of treatment. One physician visit followed by nine practitioner visits and no further physician contact fails that test.

• A practitioner adds a service the physician never ordered, such as a screening test or a new therapy
• A visit is billed for a problem the physician’s note never mentions, even if the patient is established
• Follow-up continues for months while the chart holds one physician note from the first visit

Read the physician’s notes for the period and ask who set and managed the plan. If the practitioner did, the service is the practitioner’s.

Condition two: the physician performed the initial service

Section 60.2 states the rule in one sentence: there must have been a direct, personal, professional service furnished by the physician to initiate the course of treatment of which the service performed by the nonphysician practitioner is an incidental part. The physician has to be the person who started treating the problem.

This is why a new patient rarely qualifies. If the first visit for a new problem is performed by the nurse practitioner alone, there is no physician service for the practitioner’s work to hang from. The next visit is billable incident to only after the physician personally performs an initial service for that problem.

The same reading catches the common failure. A long-standing patient seen for a brand new problem by the practitioner alone is a new problem, and the first visit for it is not incident to anything.

Condition three: direct supervision is a defined standard

Direct supervision has a definition, and it is short. The Benefit Policy Manual, Section 60.1(B), says direct supervision in the office setting does not mean that the physician must be present in the same room with the aide, but the physician must be present in the office suite and immediately available to provide assistance and direction throughout the time the aide is performing services.

The availability of the physician by telephone and the presence of the physician somewhere in the institution does not constitute direct supervision.

Medicare Benefit Policy Manual, Chapter 15, Section 60.1(B)

The current regulation adds one option. 42 CFR 410.26(a)(2) defines direct supervision by cross reference to 42 CFR 410.32(b)(3)(ii) and allows that presence to include virtual presence through real-time audio and video communications technology, excluding audio only, for services without a 010 or 090 global surgery indicator. The CY 2026 Physician Fee Schedule final rule made it permanent.

Two details. In a group practice, any physician member may be the supervising physician in the suite, and need not be the one treating the patient, but only the supervising physician may bill the service. At a patient’s home, the physician generally has to be there too, with a narrow exception for homebound patients in medically underserved areas.

Condition four: the setting decides which rule you are in

Incident to billing lives in the noninstitutional setting. The regulation defines that term as all settings other than a hospital or skilled nursing facility, and it requires the services to be furnished in a noninstitutional setting to noninstitutional patients. A hospital outpatient department is outside the rule.

For hospital patients and for skilled nursing facility patients who are in a Medicare covered stay, Section 60.1(B) says there is no Medicare Part B coverage of the services of physician-employed auxiliary personnel as services incident to a physician’s services. Those services are bundled into the facility payment, which is what MLN Matters SE0441 means when it says incident to services are not separately billable to the Part B contractor.

Split or shared visits are the arrangement most often confused with incident to billing, and the setting separates them. CMS defines a split or shared visit as an E/M visit a physician and a practitioner in the same group perform in a facility setting, billed by whoever performed the substantive portion. Its definition notes that a facility setting is one where payment incident to a physician’s services is prohibited.

When a condition fails the visit reverts to the practitioner

If the four conditions are not met, the service is not the physician’s service. It is payable, if at all, under the practitioner’s own number at 85 percent of the fee schedule. The 15 point difference is the practice’s loss, and it rarely stops at one claim, because the same pattern usually produced the visit before it.

The Office of Inspector General has returned to this repeatedly. Project OAS-25-01-003, announced on November 15, 2024, is active and asks whether Part B payments for services performed incident to physicians’ services complied with Medicare requirements. The project description states that prior OIG work found improving the transparency of incident to services to be critical to program integrity.

OIG pulled Part B claims for the first quarter of 2007 and identified days where a single physician was allowed more than 24 hours of physician work time. It sampled 250 of those physician day combinations and asked the physicians who performed each service. Physicians personally performed about half. Medicare allowed $105 million for roughly 934,000 services they performed, and $85 million for roughly 990,000 services nonphysicians performed.

OIG’s physical therapy review found the same record problem. Report OEI-09-02-00200 reviewed 70 physical therapy line items billed by physicians in the first half of 2002 and found 91 percent did not meet program requirements, valued at $136 million in improper payments. It also notes a limit that still applies: physicians are not required to indicate on the claim whether a service was furnished incident to.

What the record has to show and the control that keeps it honest

MLN Matters SE0441 puts the documentation standard in one line: the patient record should document the essential requirements for incident to service. The record has to carry the physician’s plan and continuing involvement, not merely a clean note for the service that was actually furnished.

Compliance here is an operating routine rather than a documentation rule, because the claim itself carries no marker of the arrangement. Nothing on the 1500 says a nurse practitioner saw the patient under supervision. The control that keeps the arrangement honest is a written rule about which visits qualify, plus the schedule checked against the supervision requirement before the session starts.

• Write the rule down: one signed page naming the conditions and which problems sit inside a physician plan
• Put the supervising physician on the daily schedule next to the room, not in a separate assignment sheet nobody reconciles
• Check the schedule at the start of each session. No physician in the suite means no incident to claim
• Have the physician document the plan and sign the same day, not at week end
• Report incident to volume by practitioner and payer monthly, against the physician’s own visit count

A visit that cannot be billed incident to is not a lost visit. It is a visit billed at the practitioner’s rate, or one that needs the physician to start the plan. The 2026 Medicare Physician Fee Schedule shows what each rate is worth, and the Modifier 25 documentation guide covers what happens when a physician and a practitioner both bill for one encounter. Our medical billing service reconciles incident to volume against the schedule monthly.

Questions practices ask us about this