A three-physician family practice added two nurse practitioners and a billing consultant told them to "bill everything incident-to" so Medicare would pay 100 percent of the fee schedule instead of 85. Two years later a Medicare contractor asked for forty records. In fourteen of them the supervising physician had been at the hospital when the visit occurred. In nine, the nurse practitioner had evaluated a new complaint. The contractor recalculated all forty at 85 percent, extrapolated, and sent a demand letter. The consultant was long gone.
Incident-to billing requirements are not complicated, but they are strict, and they are almost never met by a practice that treats incident-to as a default. The rule allows services furnished by non-physician staff to be billed under a physician's NPI, as if the physician had performed them, when the services are an integral part of the physician's own course of treatment and the physician is directly supervising. Every word in that sentence is a condition. Miss one and the claim was an overpayment, even when the care was excellent.
A glossary line for physicians: a non-physician practitioner (NPP) here means a nurse practitioner, physician assistant or clinical nurse specialist who has their own Medicare enrollment and could bill under their own NPI. Medicare pays NPPs 85 percent of the physician fee schedule amount when they bill under their own number. Incident-to is the mechanism that lets the same visit be paid at 100 percent under the physician's number, and the 15 points are what makes it both attractive and audited.
Key takeaways
- Incident-to applies only to established patients with an established problem for which the physician has already set the plan of care.
- The physician must be physically present in the office suite during the visit; being reachable by phone or in the building next door does not count.
- A new problem, a new patient, or a change in the plan by the NPP alone breaks incident-to for that visit, and it must be billed under the NPP's NPI.
- Incident-to is a Medicare Part B concept; many commercial payers and Medicaid programs have different or no equivalent rules.
- For most practices the 15 percent is worth far less than the audit exposure of getting it wrong, and a clean NPP-billed visit is often the better choice.
Incident-to billing requirements, one by one
| Requirement | What it means in the office | Where it fails |
|---|---|---|
| Established patient | The physician has personally seen the patient before and initiated care | A new patient seen first by the NPP; incident-to can't apply to that visit |
| Established plan of care for the problem | The physician evaluated this problem and documented the plan the NPP is following | The patient presents a new complaint; the NPP works it up and treats it |
| Direct supervision | The physician (any physician in the group, not necessarily the one who set the plan) is present in the office suite and immediately available | The physician is at the hospital, at lunch off-site, or seeing patients at another location |
| Physician's continuing involvement | The physician sees the patient often enough to reflect active participation in and management of the course of treatment | The patient has seen only the NPP for eighteen months |
| Office setting, non-institutional | Furnished in the physician's office or the patient's home, not a hospital outpatient department or a skilled nursing facility | NPP visits in a hospital-owned clinic billed as incident-to |
| Employment or contract | The NPP is an employee, leased employee or independent contractor of the physician or group | Rare in practices, but check locum and staffing arrangements |
The bill goes out under the NPI of the supervising physician, the one who was in the suite, which is not necessarily the one who set the plan of care. Practices routinely get this wrong in the other direction: they bill under the patient's regular physician who was away that day, because the system defaults to the primary care provider. The supervising physician on the claim must be the one who was physically present.
The 85 percent question, worked
Take a nurse practitioner who sees 18 Medicare patients a day, four days a week, mostly established patients with chronic conditions, coded 99213 and 99214. Suppose the average Medicare allowed amount across her visits is about $110 at 100 percent. Billed under her own NPI, the same visit allows about $93.50. The difference is roughly $16.50 per visit, about $300 a day, and around $60,000 a year if every visit qualified.
Every visit does not qualify. In a typical primary care NPP schedule, perhaps a third of visits involve a new problem or a patient the physician has not established, and on some days the supervising physician is out. Realistically the eligible share might be half. That is about $30,000 a year in additional revenue, which is real. Against it stands the exposure: if the practice bills everything incident-to and a reviewer finds a third of the sample fails, the overpayment on a two-year window of claims is the 15 percent on every failed visit, plus extrapolation, plus the possibility that a pattern of billing under an absent physician is treated as something worse than a mistake.
Our view: incident-to is worth doing when the practice can document each visit's eligibility at the time of service, meaning the scheduling system knows which physician is in the suite and the NPP's template captures whether the problem is established. It is not worth doing as a blanket setting. Practices that cannot build the workflow should bill NPP visits under the NPP's NPI, take the 85 percent, and sleep.
The four audit traps
The first is the absent physician. Reviewers compare the supervising physician's own schedule and claims to the incident-to claims. A physician who billed a hospital visit at 10:15 and supervised an office visit at 10:20 has a problem. Keep a supervision log, or make the scheduling system record which physician is designated in-suite for each half day.
The second is the new problem. The NPP note that says "patient also reports two weeks of shoulder pain; examined, likely rotator cuff strain, NSAIDs and home exercises" has just described a visit that cannot be incident-to, no matter what else happened. The fix is a decision at the end of each visit: did I address anything the physician hasn't seen? If yes, the visit bills under the NPP. Some practices have the NPP bring the physician in for that portion, which can make the whole visit a legitimate physician service if the physician does the work and documents it; simply having the physician sign the note does not.
The third is the physician who never sees the patient. Medicare's language requires the physician's active participation and management of the course of treatment. There is no fixed interval, but a patient managed entirely by the NPP for a year with no physician visit is a pattern reviewers cite. Build in a physician visit at reasonable intervals for incident-to patients.
The fourth is the wrong setting. A practice acquired by a hospital and reclassified as a provider-based outpatient department is no longer an office for incident-to purposes; hospital outpatient rules and split or shared visit rules apply instead. The billing staff often do not learn about the reclassification until the audit.
Commercial payers and Medicaid
Incident-to is a Medicare rule. Many commercial payers do not recognize it and expect the rendering provider to be the person who performed the service; some credential NPPs and pay them at their own rate, and some do not credential NPPs at all and have their own supervision billing policy. State Medicaid programs vary widely. Billing an NPP's visit under a physician's NPI to a payer that does not have an incident-to policy is misrepresenting the rendering provider, and payers treat it that way.
The practical step is a payer grid: for each of your top payers, does the payer credential NPPs, what does it pay them, and what is its written policy on NPP services billed under a physician. Our credentialing team builds this grid during NPP onboarding because it determines which payers the NPP can see patients for on day one, and under whose number.
Documentation that shows the conditions were met
The NPP's note should identify the established problem being managed and reference the physician's plan of care. It should record the name of the supervising physician present in the suite. The claim should carry that physician's NPI as the rendering provider. And the physician's own note from the visit that established the plan should exist and be findable. That is four items, and a reviewer who finds all four in the first ten records tends to stop early.
Also document the decision when a visit does not qualify. A short note that the visit was billed under the NPP because a new problem was addressed shows a reviewer that the practice knows the rule and applies it, which changes the tone of any audit from "systematic" to "occasional error." Our audit work samples incident-to claims against the physician schedule for exactly this reason, before a payer does.
Questions we hear
Can a physician in a different specialty in our group provide the direct supervision?
Under Medicare's rule, the supervising physician must be a physician member of the group who is present and immediately available; the rule does not require the same specialty, but the service must be one that physician could perform and bill. Practices with mixed specialties should get counsel's read on their specific arrangement rather than rely on a general answer.
Does telehealth supervision count as direct supervision?
Medicare has allowed direct supervision through real-time audio and video technology on a temporary and, for some services, more lasting basis in recent fee schedule rules, and the details have changed year to year. Check the current year's Physician Fee Schedule final rule language before relying on virtual presence for incident-to visits, and document the supervision method.
What about services by medical assistants and nurses?
Those are the original incident-to services: injections, blood pressure checks, wound care and similar services by staff who cannot bill on their own, billed under the physician's NPI. The same conditions apply, including direct supervision and an established plan. An MA giving a B12 injection with the physician in the suite is a textbook incident-to service; the same injection with no physician present is not billable to Medicare at all.
What to do this week
- Pull a month of claims billed under each physician's NPI where the NPP's name appears in the note, and check the physician's schedule for those times.
- Read ten NPP notes billed incident-to and mark any that address a new problem.
- Add a supervising physician field to the NPP visit template and to the scheduling system.
- Build the payer grid for NPP billing and confirm which payers have an incident-to policy at all.
- Decide, in writing, whether the practice bills incident-to by default or by exception; we recommend by exception.
