Requirements, Supervision Rules & Compliance Pitfalls
Incident-to billing allows physician practices to bill APP-provided services under the physician's NPI, collecting 100% of the Medicare physician fee schedule instead of the 85% paid when an NP or PA bills independently. It's one of the most significant revenue optimization tools in primary care and multi-provider practices. It's also one of the most frequently misused, and a top OIG audit target every year. The financial stakes here are real: a recurring gap in this area adds up to lost or delayed revenue every month.
Incident-to billing is a Medicare provision that allows services provided by a non-physician practitioner (NPP) (nurse practitioner, physician assistant, clinical nurse specialist, or other qualified auxiliary staff) to be billed under the supervising physician's NPI as if the physician personally provided the service. When billed correctly, Medicare reimburses at 100% of the physician fee schedule.
When an NPP bills independently under their own NPI, Medicare reimburses at 85% of the physician fee schedule. For a busy NP seeing 20 patients per day, the 15% difference across a full year can exceed $60,000–$100,000 in revenue per provider.
All 5 conditions must be met simultaneously. Missing any single one makes incident-to billing non-compliant, and billing under the physician NPI when requirements are not met is a False Claims Act violation.
The most commonly violated requirement: Billing incident-to when the patient presents with a new problem. An established patient with hypertension who presents for a routine BP follow-up (established plan) may be seen incident-to. If that same patient mentions new knee pain that day and the NPP evaluates it; that new problem can't be billed incident-to, even if the hypertension follow-up component could be.
New patients: defined as patients who have not received any professional service from the physician or another physician in the same group and specialty within the past 3 years, must always be seen by the physician first before incident-to billing can apply to subsequent visits. The physician must personally establish the patient, perform the initial evaluation, and document the treatment plan.
Practical implication: If an NP in your practice sees a new patient for an initial visit, that visit must be billed under the NP's NPI at 85%. The physician can't bill incident-to for an initial encounter they did not personally perform, even if they review the note afterward. Run a quarterly sample of 20 to 30 claims in this category against the supporting documentation. It's a small time investment that reliably catches five-figure problems before a payer does.
| Setting | Incident-to Allowed? | Notes |
|---|---|---|
| Physician office (own practice) | Yes | All 5 requirements must be met |
| Hospital outpatient department | No | Must bill under NPP's NPI or use split/shared rules |
| Hospital inpatient | No | Must bill under NPP's NPI or use split/shared rules |
| Independent clinic (not physician-owned) | No | NPP must bill independently |
| Federally Qualified Health Center (FQHC) | No | FQHC has its own billing methodology |
| Rural Health Clinic (RHC) | No | RHC billing methodology applies |
CMS defines three levels of supervision for Medicare purposes:
Incident-to E/M services require direct supervision. A physician who is at a different physical location, even if reachable by phone, doesn't satisfy the direct supervision requirement.
Medicare incident-to rules set the floor, not the ceiling. State scope of practice laws and state Medicaid programs may impose additional restrictions on what NPPs can do under physician supervision, or may require physician co-signature on NPP notes, alter supervision requirements, or restrict certain services entirely. Always verify both Medicare incident-to rules and applicable state regulations before implementing incident-to billing protocols.
Pull a sample of incident-to claims each quarter and test them against the five requirements. For each, confirm the patient was established, the physician had begun the plan of care, the physician was present as required, and the service was within the NPP's scope. Record the results and fix the process where claims fail. Contractors can look back three years, and on a practice with a recurring pattern here, that lookback can put a large recoupment at stake, before the cost of the appeal.
Under Medicare, a nurse practitioner or physician assistant billing under their own number is paid 85% of the physician fee schedule rate. For a moderate-complexity established visit (99214), the 2026 non-facility rate is $135.61 at 100% and $115.27 at 85%. The difference is $20.34 per visit.
That's the dollar value of the incident-to rules, and it's also the overpayment if they weren't met. A practice that bills 2,000 visits a year as incident-to when the requirements weren't satisfied has been paid $40,683 too much on those claims. The most common problems are a new problem or new patient, which aren't eligible, and a physician who wasn't in the office suite to provide direct supervision.
No. The article says a new patient, meaning someone who hasn't received professional services from the physician or a physician in the same group and specialty within the past three years, must be seen by the physician first.
Not in the hospital outpatient department or the inpatient setting, according to the article. Those services must be billed under the non-physician practitioner's NPI or under the split/shared visit rules instead.
Incident-to services are paid at 100 percent of the Medicare physician fee schedule instead of the 85 percent paid when an NP or PA bills independently. That difference is why the five requirements have to be met every time.
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RCMAXIS conducts incident-to billing audits for multi-provider practices, identifying supervision documentation gaps, new problem misclassifications, and setting-based billing errors before they trigger a payer audit.
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