Incident to Billing: The 7 Rules That Decide Whether You Can Bill It

Incident to billing is the Medicare Part B rule that lets a practice bill a nurse practitioner’s or physician assistant’s office visit under the supervising physician’s NPI, which pays 100 percent of the Physician Fee Schedule instead of the 85 percent Medicare allows when the same visit is billed under the advanced practice provider’s own number. That 15 point spread is real money on every visit, and it is why so many practices reach for the rule.

It is also one of the narrowest rules in Part B. Incident to billing works only in a non-institutional setting, only when the physician has already personally treated that patient for that problem, only when the physician stays immediately available while the visit happens, and only for Medicare. Miss any single condition and the correct claim is 85 percent under the advanced practice provider’s own NPI, not 100 percent under the physician’s.

Two developments changed the calculation. Since January 1, 2026, the supervising physician’s immediate availability can be satisfied through real time audio and video instead of physical presence in the office suite. Separately, the HHS Office of Inspector General has an open national audit of Part B payments for these services. What follows is the seven part coverage test, the situations where the rule does not reach, the payer nuance most articles get wrong, and the documentation that survives a records request.

What are the seven requirements for incident to billing?

The requirements come from 42 CFR 410.26 and Section 60 of Chapter 15 of the Medicare Benefit Policy Manual. Treat them as one combined test rather than a checklist you can partly satisfy. Every item has to be true on the date of service.

1. The setting is non-institutional. The regulation covers services furnished “in a noninstitutional setting to noninstitutional patients.” For hospital patients and for skilled nursing facility patients in a covered stay, the manual is explicit that there is no Part B coverage of these services at all. They fall under the facility benefit instead.
2. The service is integral, though incidental, to the physician’s own service. It has to belong to a course of care the physician is running, not stand on its own.
3. It is the kind of service commonly furnished in a physician’s office, and the charge appears in the practice’s bill. The cost also has to be a real expense to the practice billing for it.
4. The physician personally performed the initial service. The manual requires “a direct, personal, professional service furnished by the physician to initiate the course of treatment of which the service being performed by the nonphysician practitioner is an incidental part.” This single sentence is the source of the familiar shorthand that incident to billing does not work for new patients or new problems.
5. The physician stays actively involved. There must be “subsequent services by the physician of a frequency that reflects the physician’s continuing active participation in and management of the course of treatment.” No fixed visit interval is specified, which is exactly why this element is argued about in audits.
6. The person performing the service qualifies as auxiliary personnel. That covers any individual working under the physician’s supervision, “regardless of whether the individual is an employee, leased employee, or independent contractor,” provided the supervising physician’s relationship with the billing entity satisfies the reassignment rules.
7. Direct supervision is met for every service, not most of them. The manual adds the parenthetical that matters most here: “the direct supervision requirement must still be met with respect to every nonphysician service.”

Requirement four and requirement five carry most of the audit risk, because they are the two a busy schedule quietly breaks. A patient books with the advanced practice provider for a sore shoulder six weeks after the physician saw her for hypertension, and the visit is no longer incident to anything the physician started.

What changed for incident to billing on January 1, 2026?

Direct supervision no longer requires the physician’s body in the building. CMS made virtual supervision permanent in the CY 2026 Physician Fee Schedule final rule, and the regulatory definition at 42 CFR 410.32(b)(3)(ii) now reads:

“Direct supervision in the office setting means that the physician (or other supervising practitioner) must be present in the office suite and immediately available to furnish assistance and direction throughout the performance of the service. It does not mean that the physician (or other supervising practitioner) must be present in the room when the service is performed. The presence of the physician (or other practitioner) required for direct supervision may include virtual presence through audio/video real-time communications technology (excluding audio-only) for services without a 010 or 090 global surgery indicator.”

Read the exclusions closely, because they are where practices will get tripped up. Audio only does not qualify, so a physician reachable by phone has not met the standard. The manual already said as much in blunter terms: availability by telephone “does not constitute direct supervision.” Services carrying a 010 or 090 day global surgery indicator are also carved out and still need in person supervision.

The practical effect is that a physician covering a second location, or working from home on an administrative afternoon, can now supervise if the video connection is live and open for the duration of the service. That is a genuine scheduling gain for multi site groups. It also creates a new documentation obligation, since a supervision method that exists only as a habit is not going to persuade anyone reviewing the chart two years later.

When does incident to billing not apply?

Five situations put a visit outside the rule. None of them mean the practice goes unpaid. They mean the claim belongs under the advanced practice provider’s own NPI at 85 percent, or under a different rule entirely.

• A new patient. Nobody has initiated a course of treatment yet, so there is nothing for the visit to be incidental to.
• An established patient with a new complaint. The rule is problem specific, not patient specific. This is the most commonly missed limit in the entire ruleset.
• A facility setting. Hospital and skilled nursing visits fall under the split or shared visit rules at 42 CFR 415.140, which work on completely different mechanics.
• A commercial or Medicaid plan that says otherwise. Incident to billing is a Medicare construct. Other payers are free to write their own policy, and many do.
• A supervising physician who is neither in the suite nor on live video. Requirement seven fails, and it fails for that specific service rather than for the day.

How does incident to billing compare with the alternatives?

Three billing paths exist for care an advanced practice provider delivers. Choosing between them is a scheduling and compliance decision before it is a revenue decision.

Practices sometimes assume the 100 percent column makes the choice obvious. It does not, for a reason covered in the next section.

Is the 85 percent reduction really the same at every payer?

No, and this is where the standard advice on incident to billing quietly misleads people. The 85 percent figure is statutory for Medicare and appears in the regulations for physician assistants at 42 CFR 414.52 and for nurse practitioners and clinical nurse specialists at 42 CFR 414.56. Commercial and Medicare Advantage plans are under no such rule.

When our team ran a line by line review of the payer contracts held by the clinic we operate, the mid level reduction turned out to be four different things depending on the contract. Some agreements set the reduction explicitly in the rate exhibit. Some are silent and defer to whatever the payer’s provider manual says, which means the number can move without a contract amendment.

At least one major national commercial payer applied no reduction at all and paid advanced practice providers on the same fee schedule as physicians. And across the board, drug codes and durable medical equipment were generally not reduced for advanced practice provider rendering, because those are priced off separate methodologies rather than the physician fee schedule.

That finding reframes the whole question. If a practice’s Medicare share is modest and its largest commercial contracts apply no mid level reduction, the revenue argument for incident to billing shrinks toward nothing, while the compliance exposure stays exactly the same. Our own clinic reached that conclusion and elected to bill under each advanced practice provider’s own NPI instead. Yours might land differently. The point is that the answer lives in your payer contracts and their rate exhibits, not in a generic 85 versus 100 comparison.

Before you build a workflow around the rule, pull every contract and answer one question per payer: does this agreement reduce advanced practice provider rates, and does it say so itself or leave it to the manual? A practice with three payers and no reduction clauses is optimizing something that does not exist.

Why is incident to billing drawing more scrutiny right now?

Because it is on the federal audit calendar. The HHS Office of Inspector General added Medicare Part B Payments for Incident To Services to its Work Plan on November 15, 2024 under project number OAS-25-01-003. The stated objective is to determine whether Part B payments for these services complied with Medicare requirements.

The structural reason the rule attracts auditors is that nothing on a clean incident to claim distinguishes it from a visit the physician performed personally. The claim reports the physician as the rendering provider. Whether the seven conditions were met lives entirely in the medical record and the schedule. A reviewer cannot tell from the claim, so they ask for charts, and the practice either has contemporaneous evidence or it does not.

Incident to billing exposure is worth naming explicitly in your risk assessment rather than leaving it inside a general coding category. If you are building or refreshing the program that documents this kind of decision, our guide to building a medical practice compliance program covers the seven elements auditors expect to see and how to run the internal audits that catch a problem before a payer does.

What documentation does incident to billing require?

Medicare does not publish a template, which practices sometimes read as permission to document nothing in particular. The safer reading is that you have to be able to reconstruct each of the seven elements from the record alone. Five artifacts do most of that work.

• The physician’s own initiating note for the specific problem, with a documented assessment and plan. Findable in the chart, not inferred from a prior claim.
• The advanced practice provider’s visit note showing the care delivered follows that established plan and does not open a new problem.
• The supervising physician’s identity, recorded on the date of service. A standing designation in a policy binder is not a record of who actually supervised on a Tuesday in March.
• The supervision method, which is new work since January 2026. If the physician supervised by live video, the note should say so, because in person and virtual now carry different eligibility conditions.
• Claim level accuracy. Chapter 26, Section 10.4 of the Medicare Claims Processing Manual directs that when the practitioner who ordered the service is not the one supervising, the supervising physician’s NPI belongs in the lower unshaded portion of Item 24J.

One further discipline separates practices that hold up under review from ones that do not. Audit yourselves on the elements you cannot see on a claim, particularly the physician’s continuing involvement, and do it on a sample every quarter rather than after a payer letter arrives. Practices that also run in office diagnostics should fold the parallel supervision requirements for ancillary services into the same review, since both turn on who was present and when.

How does credentialing change the incident to billing decision?

Credentialing is the reason most practices consider the rule in the first place. A newly hired nurse practitioner cannot bill under her own NPI until she is enrolled with the payer, and enrollment takes as long as it takes. Incident to billing looks like an elegant bridge across that gap.

Used that way it is a trap, for a reason worth being precise about. The rule has no enrollment exception. If the visit fails any of the seven conditions, an unenrolled provider’s care is not billable to Medicare under the physician’s NPI simply because the alternative is inconvenient. Practices that lean on the rule as enrollment cover tend to accumulate exactly the claims an audit is designed to find.

The durable fix is upstream. Start insurance credentialing at the offer letter rather than the start date, keep every provider’s credentialing file current so applications do not stall on missing documents, and treat Medicare provider enrollment for a new advanced practice provider as a hiring milestone with an owner and a date. Practices that plan enrollment alongside their hiring pipeline rarely need a bridge at all. Where the two functions intersect on the billing side, our overview of credentialing in medical billing walks through how enrollment status drives what you can legitimately submit.

Frequently asked questions about incident to billing

Can incident to billing be used for a new patient?

No. The Medicare Benefit Policy Manual requires a direct, personal, professional service by the physician to initiate the course of treatment before an advanced practice provider’s service can be incidental to it. With a new patient no such course of treatment exists, so the visit should be billed under the advanced practice provider’s own NPI at 85 percent of the fee schedule.

Does incident to billing apply to commercial insurance?

Not automatically. Incident to billing is a Medicare Part B rule found at 42 CFR 410.26. Commercial and Medicare Advantage plans set their own policy on advanced practice provider billing and supervision, and those policies vary widely between payers. Check each contract and provider manual before applying Medicare logic to a non-Medicare claim.

Can a physician supervise by video for incident to billing in 2026?

Yes, for most office services. Effective January 1, 2026, the regulatory definition of direct supervision permits the supervising practitioner’s virtual presence through real time audio and video technology. Audio only does not qualify, and services with a 010 or 090 day global surgery indicator are excluded and still require in person supervision.

What is the difference between incident to billing and a split or shared visit?

Setting and mechanics. Incident to billing applies in non-institutional settings such as a physician’s office and turns on the physician having initiated the course of treatment while remaining immediately available. Split or shared visits apply in facility settings, involve two practitioners who could each bill the visit independently, and pay the one who performed the substantive portion, meaning more than half the total time or a substantive part of the medical decision making.

Is incident to billing worth it if our commercial payers do not reduce advanced practice provider rates?

Often not. The 85 percent reduction is statutory only for Medicare, and some commercial contracts apply no reduction at all. If Medicare is a small share of your volume and your largest commercial contracts pay advanced practice providers at the physician rate, incident to billing adds audit exposure without meaningful revenue. Read the rate exhibits in your own contracts before building a workflow around the rule.

Getting the decision right for your practice

Incident to billing rewards practices that can prove things and punishes practices that assume them. Two concrete steps put you on the right side of that line. Pull your payer contracts and find out whether the mid level reduction you are trying to avoid actually exists at your largest plans. Then sample twenty recent claims billed under a physician’s NPI for care an advanced practice provider delivered, and see whether the chart alone establishes the initiating visit, the continuing involvement, and who supervised on that date.

If that exercise surfaces gaps, we can help you close them. Practice Management Consultancy advises medical practices on billing compliance, payer contracting, and credentialing. We are consultants rather than a billing vendor, so we work alongside whoever handles your claims rather than taking the function over. Our team runs its own clinic, which is why the guidance above comes with contract level detail instead of generalities. See how our consulting engagements work, or contact us to talk through your own situation.

This article is general information for medical practice operators, not legal or coding advice. Medicare rules change, and payer policies differ. Verify current requirements against the Medicare Benefit Policy Manual and your own payer contracts before changing how you bill.

Disclosure: our team operates and manages the medical practice referenced in first-person examples on this site.