Medicare incident-to requirements at a glance
Incident-to billing requires: (1) the patient is established with the supervising physician, (2) the physician personally performed the initial visit and established the plan of care, (3) the NPP follows that established plan, (4) the supervising physician is physically present in the office suite (direct supervision) when the service is delivered, (5) the service is the type commonly furnished in physician offices, (6) the practice is the physician's office (POS 11). New patient visits and any change to an established plan cannot be billed incident-to — they must be billed under the NPP's NPI at 85%.
- Established patient + established plan only
- Direct supervision: physician in office suite
- POS 11 (office) — not hospital or facility
- Source: 42 CFR 410.26
Medicare Incident-To Billing: The Rules That Matter
By MedPrecision Editorial Team · Published
Incident-to billing lets a Medicare claim for services performed by a non-physician practitioner (NP, PA, CNS) be billed under the supervising physician's NPI at 100% of the physician fee schedule, rather than 85% under the NPP's own NPI. The math makes the strategy attractive — and the OIG audit history makes the rules unforgiving. Practices that bill incident-to without satisfying every requirement face False Claims Act exposure that can dwarf the original revenue lift.
The Regulatory Source
Medicare incident-to billing is defined at 42 CFR 410.26 and elaborated in Chapter 15, Section 60 of the Medicare Benefit Policy Manual. The regulation defines services and supplies that are 'furnished as an incident to a physician's professional services' and the conditions under which Medicare will pay them as if performed by the physician. The intent of the rule is to allow physicians to use auxiliary personnel — including nurse practitioners, physician assistants, and clinical nurse specialists — to extend the physician's practice while maintaining the physician's clinical relationship with the patient. The 100% reimbursement reflects that the physician retains responsibility for the patient and is supervising the encounter; the 85% reimbursement under the NPP's own NPI reflects independent NPP practice without that supervisory link.
The Six Specific Requirements
All six conditions must be met for any single encounter to qualify as incident-to. First, the patient must be established with the supervising physician — meaning the physician has personally seen the patient previously and established a treatment plan. Second, the patient's current presenting problem must be one for which the physician has previously evaluated and established a plan of care; new problems for the established patient cannot be billed incident-to. Third, the NPP must be following the established plan; any change to the plan of care must be made by the physician, not the NPP. Fourth, the supervising physician must be physically present in the office suite (not necessarily in the room, but in the same physical office space) and immediately available to provide assistance — this is 'direct supervision' under 42 CFR 410.32. Fifth, the service must be of a type commonly furnished in physician offices. Sixth, the encounter must occur in the physician's office (POS 11) — not in a hospital, skilled nursing facility, or other place of service.
The 100% vs 85% Math
Medicare reimburses NPP services billed under the physician's NPI (when incident-to requirements are met) at 100% of the physician fee schedule. The same services billed under the NPP's own NPI reimburse at 85% of the physician fee schedule. For a 99213 office visit with a Medicare allowable of approximately $93 (national average, 2026 rates), the difference is roughly $14 per encounter. At a practice with two NPPs each seeing 25 Medicare patients per day, the annualized differential is approximately $182,000 per year — meaningful enough to motivate aggressive billing, and meaningful enough to make the OIG audit risk substantial when requirements are not met.
The OIG Audit History
Incident-to billing has been an OIG Work Plan focus area for over a decade. OIG audits and reports have repeatedly found significant non-compliance, including encounters where the supervising physician was not in the office suite during the NPP service, encounters billed incident-to where the NPP was treating new patients or new problems, and encounters where no supervising physician of record was identifiable. Settlements under the False Claims Act stemming from incident-to billing have reached eight figures for some practices. The pattern in OIG findings is consistent — practices that bill incident-to as a default for NPP encounters without verifying each individual encounter's compliance accumulate exposure quickly. Practices that bill incident-to selectively and document the qualification on a per-encounter basis are far less exposed.
Documentation Requirements
Documentation must establish that all six requirements were met for the specific encounter. The chart should reflect the established patient relationship (prior physician encounter on file with established plan), the established problem the NPP is addressing, the NPP following the established plan rather than developing a new plan, the identity of the supervising physician for that encounter (sometimes called the 'supervising physician of record'), and that the supervising physician was physically in the office suite during the encounter. The supervising physician's identity must be on the claim — best practice is to bill the encounter under the supervising physician's NPI as the rendering provider. Some practices document the supervising physician's office presence via a daily attestation or a system log; either is acceptable as long as it is contemporaneous and reliable.
Common Compliance Failures
Five failure patterns produce most incident-to compliance issues. First, billing incident-to for NPP encounters with new patients — the established patient requirement is the single most-violated condition because it requires verifying the prior physician relationship before the encounter. Second, billing incident-to for established patients with new presenting problems that the physician has not evaluated. Third, supervising physician not physically present in the office suite at the time of service — frequently because the physician is at a hospital, on lunch, or off-site at the moment of the NPP encounter. Fourth, lack of documentation identifying the specific supervising physician for the encounter. Fifth, applying incident-to logic to services rendered in non-office settings (hospital outpatient, urgent care, SNF) — the rule is office-only. The first three failures are the bulk of the audit findings.
When to Bill Under the NPP's NPI Instead
Incident-to is not always the right answer. Bill the encounter under the NPP's own NPI at 85% when any of these conditions exist: the patient is new to the practice, the patient is established but presenting with a new problem the physician has not evaluated, the supervising physician is not in the office suite, the encounter is in a non-office place of service, the NPP is making changes to the established plan of care. The 15% reimbursement differential is meaningful but not catastrophic, and clean NPP billing is far preferable to compliance exposure. Many compliance-conservative practices adopt a default of billing under the NPP's NPI and only switching to incident-to billing when the encounter is verified to meet all six requirements — a defensible posture that produces slightly less revenue but far less audit risk.
Common Questions
Common questions about medicare incident-to billing rules (2026).
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Get a Free Billing Audit arrow_forwardWhat is incident-to billing in Medicare?
Incident-to billing is a Medicare provision under 42 CFR 410.26 that allows a service performed by a non-physician practitioner (nurse practitioner, physician assistant, clinical nurse specialist) to be billed under the supervising physician's NPI and reimbursed at 100% of the physician fee schedule, rather than under the NPP's own NPI at 85%. The 15% reimbursement differential is the financial driver. The provision requires that the patient be established with the supervising physician, that the NPP follow an established plan of care for an established problem, that the physician be physically present in the office suite during the service, and that the encounter occur in the physician's office (POS 11). All six conditions must be met for any single encounter to qualify; failure on any condition disqualifies that encounter from incident-to billing.
Can a new patient visit be billed incident-to?
No. New patient visits cannot be billed incident-to under any circumstances. The first of the six incident-to requirements is that the patient must be established with the supervising physician, meaning the physician has personally seen the patient previously and established a plan of care. A new patient by definition has no prior physician encounter, so the established patient relationship does not exist. New patient encounters with an NPP must be billed under the NPP's own NPI at 85% of the physician fee schedule. This is among the most-violated incident-to rules in OIG audits — practices sometimes bill all NPP encounters incident-to as a default, including new patient visits, and accumulate measurable False Claims Act exposure as a result.
Does the physician need to be in the room for incident-to?
No — the physician does not need to be in the exam room with the patient and NPP. The supervision standard is 'direct supervision,' defined at 42 CFR 410.32 as the physician being physically present in the office suite (the same physical office space) and immediately available to provide assistance and direction throughout the procedure. The physician can be in another exam room, in their personal office, or anywhere else within the suite — but they cannot be at a hospital, on a lunch break off-site, at home, or otherwise unavailable. Practices need a reliable mechanism to document that the supervising physician was in the suite at the time of the NPP encounter — typically a contemporaneous daily attestation, a sign-in/sign-out log, or a system-generated time stamp tied to physician presence.
Can incident-to be used in a hospital outpatient setting?
No. Incident-to billing applies only to services rendered in the physician's office, generally POS 11. Hospital outpatient settings (POS 19, POS 22), skilled nursing facilities, and other non-office places of service do not qualify for incident-to billing. NPP services in those settings must be billed under the NPP's own NPI at 85% of the physician fee schedule. Some practices misapply incident-to in hospital-affiliated outpatient clinics or provider-based clinics — this is one of the OIG audit findings that has produced significant False Claims Act settlements. The place-of-service code on the claim is one of the easiest audit triggers; CMS data analytics flag claims billed under a physician NPI with NPP rendering history at non-office places of service.
What documentation is needed to support incident-to billing?
The chart must establish all six conditions for the specific encounter. Documentation should include: the prior physician encounter on file demonstrating the established patient relationship and the established plan of care; the NPP's note for the current encounter identifying the established problem being addressed and the plan being followed (not modified); the identity of the supervising physician of record for that encounter; contemporaneous evidence that the supervising physician was physically in the office suite during the encounter (daily attestation, sign-in log, or time-stamped electronic record); the place of service confirmed as the physician's office (POS 11). On the claim itself, the supervising physician's NPI must be the rendering provider. OIG audits routinely look for missing supervising physician documentation as the easiest finding — a practice that cannot identify the specific supervising physician for an incident-to encounter is unable to defend the billing.
Should I just bill all NPP visits under the NPP's NPI to avoid risk?
Many compliance-conservative practices adopt this approach. The 15% reimbursement differential between 100% (incident-to) and 85% (under NPP's NPI) is meaningful — at a typical Medicare-heavy practice it can represent $50,000 to $200,000 per year per NPP — but the False Claims Act exposure from improperly billed incident-to encounters has produced multi-million dollar settlements at practices with documentation gaps. A defensible middle ground is to bill incident-to selectively and only when the encounter has been verified against all six requirements, with documentation contemporaneously captured. Many practices accomplish this by defaulting NPP claims to bill under the NPP's NPI in the practice management system and switching to incident-to billing only for encounters affirmatively verified against the requirements. This produces slightly less revenue than aggressive incident-to billing and dramatically less audit risk.
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