Incident to billing is a Medicare Part B rule that lets a practice bill a nurse practitioner’s or physician assistant’s office visit under the supervising physician’s National Provider Identifier, at 100 percent of the physician fee schedule instead of 85 percent. It only works for established patients on an existing plan of care, and the physician must be immediately available to supervise. Miss one requirement and the claim drops to 85 percent, or draws an audit. For more guidance on provider enrollment requirements, see our Physician Assistant Credentialing Requirements and How to Enroll in PECOS Medicare guides.
What Is Incident to Billing?
Incident to billing lets a practice report a nurse practitioner’s or physician assistant’s visit as if the physician performed it, collecting 100 percent of the Medicare Physician Fee Schedule rate instead of the 85 percent an NPP earns billing under their own NPI. You’ll also see this shortened to ITB in some payer manuals. For related credentialing requirements, see our Physician Assistant Credentialing Requirements
The rule lives in 42 CFR 410.26 and in Chapter 15 of the Medicare Benefit Policy Manual. It’s Medicare’s compromise: NPPs can’t bill at the physician rate for their own independent patient relationships, but once a physician has diagnosed a problem and built a plan of care, routine follow up work on that same plan can ride along at the full rate. Some commercial payers and state Medicaid plans allow a version of it too, but their rules rarely match Medicare’s exactly, so never assume a private payer follows the same playbook.
How Does Incident to Billing Work?
The mechanics come down to a hand off between two providers. A physician sees an established patient, diagnoses the problem, and documents a plan of care. That first visit bills under the physician’s own NPI, because the physician performed it directly, not incident to anything.
On the follow up visits, an NP or PA sees the same patient to continue that same plan, a blood pressure check, a medication refill, a wound recheck. If the physician is available to supervise at the time of that follow up visit and every other condition holds, the practice bills the visit under the physician’s NPI instead of the NPP’s, and Medicare pays the full rate. The moment the NPP evaluates something the plan of care doesn’t cover, the hand off breaks and the visit has to bill under the NPP instead.
For related guidance, see our Physician Assistant Credentialing Requirements.
What Are the Incident to Billing Requirements?
CMS lists nine conditions in the regulation, but they collapse into six practical checks a biller can run on every chart before submitting the claim.
- Established patient, established problem. The visit has to continue a diagnosis the physician already made, not address anything new.
- Physician initiated plan of care. A physician, not the NPP, created the original treatment plan and documented it.
- Direct supervision at the time of service. A qualified physician must be immediately available during the visit, in person or, as of 2026, by real time video.
- Same employment relationship. The supervising physician and the NPP need to work for the same practice, whether as an employee, leased employee, or contractor.
- Noninstitutional setting only. The service has to happen in the physician’s office (place of service 11), not a hospital or skilled nursing facility.
- Both providers enrolled with Medicare. Neither can be excluded from federal healthcare programs or have a lapsed enrollment.
Miss any one of these and the claim isn’t incident to. It’s just a visit that has to bill under the NPP who actually performed it.
What Changed in Incident to Billing for 2026?
The single biggest shift in incident to billing this year has nothing to do with new codes. It’s about where the supervising physician has to stand. Historically, direct supervision meant the physician had to be physically present in the office suite while the NPP saw the patient. In the CY 2026 Physician Fee Schedule final rule, issued October 31, 2025, CMS made permanent a change that started as a flexibility introduced during the pandemic: direct supervision can now be satisfied through real time, two way audio and video technology instead of physical presence, effective January 1, 2026.
Audio only calls don’t count. The physician has to be able to see and hear the encounter in real time and step in immediately if needed. There’s also an exception worth knowing: procedures carrying a 10 day or 90 day global surgery period still require the physician to be physically on site, because CMS decided those higher risk services need someone in the building.
Most practices we talk with assume this rule means a physician can supervise from anywhere with a laptop open. That’s mostly true, but only for the services that fall outside a global period, and only if the platform actually delivers live video, not a phone call logged as a virtual visit.
If your practice runs multiple NPs seeing established patient follow up visits while the physician is at the hospital or in another exam room, this rule is worth building a real workflow around in 2026, not just a policy memo nobody reads. Our provider credentialing team can confirm every supervising physician and NPP on your incident to roster holds active Medicare enrollment before you lean on the new flexibility. You can also review our Provider Enrollment Services and Insurance Credentialing Services for related enrollment and credentialing support.
What Is the Incident to Billing Modifier?
Traditional Medicare doesn’t require a special modifier for a compliant incident to claim. The NPP codes the visit the same way any provider would code an E/M visit, typically established patient office codes 99212 through 99215, and the claim goes out under the supervising physician’s NPI with no flag attached.
Where the modifier question actually matters is outside Medicare. Modifier SA shows up in some state Medicaid programs and commercial payer policies to identify a nurse practitioner’s involvement in the visit, but appending SA doesn’t guarantee the 100 percent rate. Some payers use SA and still reimburse at 85 percent. Others prohibit incident to billing entirely and require the rendering NPP to bill under their own number no matter what. If your practice bills across Medicare, Medicaid, and five commercial plans, you’re effectively running three different rule sets for the same visit type, and that’s exactly where coding accuracy tends to slip. Our medical billing and coding services team builds payer-specific rule sets into the claims workflow so the same encounter doesn’t get coded three different ways by accident.
Incident to Billing vs. Split/Shared Visit Billing
Practices confuse these two constantly, and the confusion gets expensive because the rules run in almost opposite directions.
The plain version: incident to lives in the office and rewards a physician who set the plan and stays reachable. Split or shared billing lives in facilities and rewards whoever actually did the substantive medical decision making that day, per the American Academy of Family Physicians’ guidance on the two rules.
Incident-to errors are one of the fastest ways to trigger a payer audit.
Our Denial Management Services team reviews incident-to claims against CMS documentation requirements before submission, not after they bounce back. See where your denial rate stands before Medicare finds the gap for you.
Incident to Billing Examples: When It Works and When It Doesn’t
Example 1, valid. A physician at an internal medicine practice in Tampa diagnoses a patient with hypertension and documents a plan: start Losartan, recheck blood pressure in two weeks, NP may adjust the dose at the next visit. The NP sees the patient two weeks later while the physician is in an adjacent exam room. This bills at 100 percent under the physician’s NPI.
Example 2, invalid, new patient. A physician assistant sees a patient who has never been seen by the practice before. The physician never examines the patient and only signs off on the note afterward. Because the physician didn’t create the plan of care and the patient isn’t established, this has to bill under the PA’s own NPI at 85 percent, regardless of that later signature.
Example 3, invalid partway through the visit. An NP sees an established congestive heart failure patient for a routine medication check, a valid incident to scenario, but the patient also mentions new shoulder pain. The NP examines the shoulder and orders an X ray. That portion of the visit addresses a problem with no established plan of care, so it no longer qualifies as incident to and reverts to the NP’s own NPI.
Example 4, valid under the 2026 update. A physician supervises an established patient rash recheck by live video from another office in the same group while the NP conducts the visit in person. Because the service doesn’t carry a global surgery period and the supervision happens in real time by audio and video, this now satisfies direct supervision under the CY 2026 rule.
What Happens If You Bill Incident to Incorrectly?
The Office of Inspector General has an active national audit of Medicare Part B incident to payments underway, with results expected in FY 2026, and incident to compliance sits near the top of OIG’s current work plan. That’s not background noise. It means practices billing incident to today are more likely than in past years to have those specific claims reviewed.
he financial exposure isn’t abstract either. Under the False Claims Act, civil penalties for a false claim currently run from roughly $14,308 to $28,619 per claim under the 2025 inflation adjustment, on top of triple the government’s actual damages. A practice submitting a few hundred incident to claims a month doesn’t need many audit findings before that number gets uncomfortable. Add an unenrolled NPP or a lapsed credential into the mix, and a routine credentialing gap turns into a false claims problem overnight. Our provider credentialing services can help practices maintain accurate provider enrollment and credentialing records.
Quick gut check: if you can’t point to the note where the physician documented the original plan of care, and you can’t name who was supervising on the date of service, that claim probably shouldn’t have gone out as incident to.
Should Your Practice Bill Incident to In House?
Most practices land in one of two camps. Some skip incident to billing entirely because it feels risky, and quietly leave 15 percent on the table for every NP and PA visit that could have qualified. Others use it inconsistently, sometimes correctly, sometimes not, which is arguably worse, because it means some of the claims sitting in your revenue cycle right now are audit bait and nobody’s flagged them.
A documented, repeatable process closes that gap: a standard plan of care template physicians fill out at the initial visit, a supervision log tied to the schedule, and a coder who checks all six conditions before the claim goes out, not after a denial comes back. If building and maintaining that workflow isn’t where you want your front office spending its time, that’s exactly the kind of work incident to billing services handle inside a broader revenue cycle management engagement. It’s worth comparing what that actually costs against keeping it in house; our in-house vs. outsourced medical billing breakdown walks through the real numbers on both sides.
Protect your 100% reimbursement rate and shield your practice from audits.
Getting incident-to billing right protects both your revenue and your practice from audit exposure. Medicotech’s certified billers build compliant incident-to workflows into your claims process from day one, so your NPs and PAs get billed correctly every time. Book your free billing audit and see exactly where your current process stands today.
Frequently Asked Questions
What is incident to billing?
Incident to billing is a Medicare Part B billing method that lets a nurse practitioner’s or physician assistant’s visit be billed under the supervising physician’s NPI at 100 percent of the fee schedule rate. It applies only to established patients on a physician initiated plan of care, with the physician directly supervising the visit.
What is the definition of incident to billing in Medicare?
Under 42 CFR 410.26, incident to billing means services and supplies furnished by auxiliary personnel that are an integral, incidental part of a physician’s professional service, furnished in a noninstitutional setting under the physician’s direct supervision, and billed as though the physician performed them.
What are the incident to billing guidelines for 2026?
For 2026, the core guidelines stay the same: established patient, physician initiated plan of care, same practice employment, and direct supervision. The one major change is that CMS made virtual direct supervision permanent as of January 1, 2026, letting the physician supervise by real time audio and video instead of standing in the office suite for most services.
What is the incident to billing modifier?
Traditional Medicare does not require a special modifier for incident to claims; the NPP codes the service normally, and the practice bills it under the supervising physician’s NPI. Some state Medicaid programs and commercial payers use modifier SA to flag an NP or PA visit, but it does not guarantee 100 percent reimbursement outside Medicare.
Can incident to billing be used for a new patient?
No. Incident to billing requires an established patient with an existing plan of care that the physician personally created. A new patient visit, or a new problem raised during an otherwise established visit, must be billed under the treating NPP’s own NPI at 85 percent.
What is an example of incident to billing?
A physician diagnoses a patient with hypertension and documents a treatment plan. Two weeks later, the nurse practitioner sees the same patient for a follow up visit and blood pressure check while the physician is immediately available in the suite. That visit qualifies as incident to and bills at 100 percent under the physician’s NPI.
What is the difference between incident to billing and split or shared billing?
Incident to billing applies in the physician’s office (POS 11) for established patients and pays 100 percent when compliant. Split or shared billing applies in facility settings like hospitals, covers new or established patients, requires modifier FS, and pays 100 percent only if the physician performed the substantive portion of the visit.
What codes are used for incident to billing?
Incident to billing does not use a separate code set. The NPP selects the same CPT, HCPCS, and ICD-10-CM codes any provider would use for that visit, most commonly established patient E/M codes 99212 through 99215, and the practice submits the claim under the supervising physician’s NPI.
How do I bill incident to correctly?
Confirm the patient is established with a physician created plan of care, confirm a qualified physician is directly supervising at the time of service, code the visit normally, bill under the supervising physician’s NPI, and document the plan of care and supervision in the note so an auditor can verify all elements without asking.
What documentation does incident to billing require?
The note should identify the physician who created the plan of care, confirm the visit follows that existing plan, and name the physician who directly supervised the encounter, including whether supervision was in person or by real time audio and video. Both the physician and the NPP should be identifiable in the record.
