Incident-To Billing Rules for Medicare

What Is Incident-To Billing?

Incident-to billing is the Medicare Part B rule in 42 CFR 410.26 that pays for services and supplies furnished as an integral, though incidental, part of a physician's or practitioner's service in diagnosing or treating an injury or illness. The service is billed by the supervising practitioner, not by the person who performed it.

Regulation 410.26(b)(5) says only the supervising physician or practitioner may bill Medicare for incident-to services. The Medicare Benefit Policy Manual, chapter 15, section 60, gives the coverage detail, and the Claims Processing Manual, chapter 12, section 30.6.4, covers E/M visits furnished this way.

In section 60 "physician" includes a physician assistant, nurse practitioner, clinical nurse specialist, nurse midwife and clinical psychologist who are authorized to receive payment for incident-to services of their own.

What Conditions Must Every Incident-To Service Meet?

All of the following, taken from 42 CFR 410.26(b). Missing any one takes the service out of incident-to.

Auxiliary personnel can be employees, leased employees or independent contractors, but under 410.26(a)(1) they cannot be excluded by the OIG or have revoked Medicare enrollment, and they must meet any State licensure requirement. The supervisor also needs a valid reassignment relationship with the entity that bills, under section 60.1 B of the manual.

What Level of Supervision Does Incident-To Require?

Direct supervision is the default. Under 42 CFR 410.32(b)(3)(ii), direct supervision in the office setting means the supervising practitioner is in the office suite and immediately available to help throughout the service, though not necessarily in the same room.

Since January 1, 2026, that presence can be virtual. The CY 2026 physician fee schedule final rule, as written in 410.26(a)(2), lets it include real-time audio and video, excluding audio-only, for services without a 010 or 090 global surgery indicator. CMS's Telehealth FAQ (question 10) confirms the date and says this covers most incident-to services.

The supervisor does not have to be the practitioner treating the patient, but must be the one who bills. In an institution such as a nursing home, availability by telephone and presence somewhere in the building is not direct supervision, says section 60.1 B.

Does Incident-To Apply to New Patients and New Problems?

Not for the first visit. Section 60.2 of the manual requires that the physician personally furnish a direct professional service that initiates the course of treatment, followed by later physician services at a frequency that shows active participation in and management of the treatment.

A new patient's first visit, or a new problem for an established patient, therefore has no earlier physician service to attach to. The nurse practitioner or physician assistant bills that visit under their own NPI. Later follow-up visits in the course of treatment the physician set can qualify, if direct supervision is met for each one.

Does Incident-To Apply in the Hospital Outpatient Department?

No. Regulation 410.26(a)(6) defines a noninstitutional setting as every setting other than a hospital or skilled nursing facility. Section 60.1 B adds that for hospital patients, and skilled nursing facility patients in a covered stay, there is no Part B coverage of a physician's auxiliary personnel as incident-to; the hospital or facility is paid under its own benefit.

Section 60 B of the manual says hospital services incident to a physician's or practitioner's services to outpatients are paid to the hospital by its A/B MAC. In a hospital-based clinic, a shared physician and NPP visit falls under the split/shared visit rules. The facility side is covered under provider-based billing.

How Is an Incident-To Service Billed, and What Does It Pay?

On the CMS-1500, the supervising practitioner's NPI is the rendering provider. Chapter 26 item 24J says that for a service furnished incident to a practitioner, when the person who ordered the service is not supervising, enter the supervisor's NPI. Under section 30.6.4 of chapter 12, when an NPP furnishes an E/M service incident to a physician, the physician bills the CPT code that describes it. When a nonphysician employee furnishes it, not as part of a physician service, the physician bills 99211.

Medicare pays the fee schedule amount for the rendering NPI on the claim (chapter 12, section 30.6.1). A nurse practitioner billing under their own NPI is capped at 85 percent of that amount by 42 CFR 414.56(c). That difference is what is at stake when a reviewer tests an incident-to claim.

What Are the Audit Risks, and What Goes Wrong on the Remittance?

The risk is billing under the physician when a condition was not met. A reviewer testing a claim has to be able to answer the rule's own questions: was there a physician initial service, was supervision met on the date, was the setting noninstitutional, and does the supervisor have a valid relationship with the billing entity.

These X12 codes can appear when the rendering provider or provider type is questioned. The last column is where to look, not a statement of cause.

Controls that answer those questions before the claim goes out:

1. Document the physician's initial service for each course of treatment.
2. Record the supervising practitioner's presence in the suite, or the audio and video connection, for the date of service.
3. Check that the setting is noninstitutional before the claim is built.
4. Confirm auxiliary staff against the OIG exclusion list and State licensure.
5. Confirm the supervisor's reassignment to the billing entity.

What If Incident-To Claims Were Paid When They Should Not Have Been?

Treat it as an overpayment. 42 CFR 401.305(b) requires reporting and returning it 60 days after it is identified, and 401.305(f) reaches back 6 years from the date of receipt. Our 60-day overpayment rule page covers the process.

If a MAC denies or recoups a claim you believe met the conditions, the first appeal is a redetermination filed within 120 calendar days of receiving the notice under 42 CFR 405.942(a), with receipt presumed 5 calendar days after the notice date. Later levels are on Medicare appeal levels. Our billing and coding audits cover incident-to claims, and our medical billing team handles the claims after that.