Modifier 26 vs TC: 3 Rules for In-Office Testing

Modifier 26 tells a payer you are billing only the physician half of a diagnostic test: the supervision, the interpretation, and the written report. Modifier TC tells the payer you are billing only the technical half, meaning the equipment, the staff who ran it, the supplies, and the overhead. Most independent practices that bought their own diagnostic equipment need neither one. When a single practice owns the machine, employs the staff who perform the study, and employs the physician who writes the interpretation, the code is reported globally, with no modifier appended, and the payment covers both halves.

That resolves the question for a large share of the practices that ask it. The rest of this guide covers the cases where the split genuinely applies, how to check whether a code can be divided at all, what Medicare wants in the chart before it pays either component, and one same-day payment rule that surprises practices reporting more than one vascular study in a visit.

What modifier 26 and modifier TC actually divide

A diagnostic test has two economic halves. The professional component is the physician’s work: ordering and supervising the study at the required level, reading the tracings or waveforms, exercising clinical judgment, and producing a signed report that becomes part of the record. Modifier 26 identifies that half on a claim. The technical component is everything the practice provides to make the study happen: the device itself, its maintenance and consumables, the clinical staff time, the room, and the practice’s overhead. Modifier TC identifies that half.

Added together, the two components equal the global service. The split exists because in much of medicine the two halves come from different pockets. A radiologist reading images produced by a hospital supplies only the professional work. The hospital supplies only the technical resources. Each bills its own piece. In an independent practice that bought a device and reads its own studies, both pockets are the same pocket, so there is nothing to divide.

How to tell whether a code can be split at all

Not every code has two components. CMS settles the question in the National Physician Fee Schedule Relative Value File, which carries a PC/TC indicator on every line. An indicator of 1 means the code has both a professional and a technical component, and that modifier 26 and modifier TC are available. Other indicators describe codes that are physician-work only, technical only, or global-only tests where no split is permitted. Appending modifier 26 to a code that has no professional component is a straightforward rejection.

For the codes an in-office vascular and autonomic testing program actually reports, we pulled the values directly from the CMS CY2026 file rather than repeating a secondhand summary. All three are splittable, and each carries a different balance between the two halves.

The three billing scenarios, and the one your practice is probably in

Every diagnostic test lands in one of three arrangements, and the arrangement decides the modifier.

Global, with no modifier. One entity owns the equipment, employs or contracts the personnel who perform the study, and employs the interpreting physician. This is the ordinary case for an independent practice that has brought vascular testing in-house and reads its own results. Report the code by itself. Medicare attaches one further condition that a single-site practice meets without thinking about it: the two components must also fall within the same physician fee schedule payment locality. A group whose reading physician sits in a different locality from the equipment bills the components separately even though one entity owns both. Adding modifier 26 here does not protect you from anything; it simply drops the larger half of the claim.

Modifier 26 alone. A physician interprets a study that someone else’s equipment and someone else’s staff produced. The reading physician bills the code with modifier 26, and the entity that owns the equipment bills separately. This is the arrangement to check carefully if your practice sends patients elsewhere for testing and a physician in your group reads the result, or if a specialist reads studies performed at a facility.

Modifier TC alone. Your practice performs the study but an outside physician interprets it and bills the professional half under a separate arrangement. Place of service matters here as well. When a test is furnished to a hospital patient, the facility payment system, not the physician fee schedule, generally pays for the technical resources, and the physician reports the professional component only.

Why the technical component carries most of the value in these studies

The table above is worth a second look, because the two halves are nowhere near equal for extremity arterial testing. Of the 4.00 total non-facility relative value units CMS assigns to 93923, 3.36 sit in the technical component and 0.64 in the professional component. Roughly five sixths of the published fee-schedule value of that study is attached to owning the equipment and running it, not to reading it.

The autonomic codes are more balanced. Cardiovagal testing under 95921 splits close to evenly, and sudomotor testing under 95923 sits between the two. Two practical points follow. A practice reading studies it does not perform should not expect the professional line to resemble the global line. And a practice that owns its equipment but appends modifier 26 out of habit, or because a billing template carries the modifier forward from a prior payer relationship, is understating its own claims in a way that no denial will flag. Nothing rejects; the payment is simply smaller than the work performed.

Relative value units are national. Actual payment depends on the annual conversion factor and your geographic locality, and the values change every January. The underlying figures are published by the Centers for Medicare & Medicaid Services in its Physician Fee Schedule relative value files, released each year. Confirm current amounts and coverage terms with your own Medicare Administrative Contractor before you rely on them.

What the record must show before you bill either component

Medicare draws a firm line between an interpretation and report and a review of findings, and that line is the most common reason a professional-component claim fails. The Medicare Claims Processing Manual (Publication 100-04, Chapter 13, section 100.1) states that a professional-component claim based on a review of findings, without a complete written report, does not meet the conditions for separate payment, and gives a bare notation such as “EKG-normal” as an example of what will not suffice. A note reading “ABI reviewed, abnormal” is the same shape of entry. It does not support modifier 26. What supports the professional component is a distinct, signed, dated report that states the findings, interprets them, and is retrievable from the chart as its own document. The same expectation applies to the interpretation inside a global claim; billing globally does not lower the bar, it simply means one entity is answering for both halves.

The rest of the record has to do its share too. The chart needs the documented symptoms or clinical indications that made the study medically necessary before it was ordered, and it needs evidence that the result changed or confirmed something in the plan of care. Contractors that open a targeted probe and educate review ask for exactly these elements, and they ask for them on a sample of claims you cannot choose. Supervision level is a separate requirement that travels alongside the modifier question, covered in more detail in our guides to incident to billing and who is permitted to perform an ABI test.

The same-day reduction that catches multi-study visits

Here is the wrinkle that a general modifier 26 explainer will not mention, because it only bites practices reporting more than one cardiovascular study in a day. In the same CMS file that carries the PC/TC indicator, 93923 also carries a multiple-procedure indicator of 6. That flags it for the diagnostic cardiovascular multiple procedure payment reduction: when two or more of these studies are furnished to the same patient on the same day by the same practice, the study with the highest technical value is paid in full and the technical component of each additional study is reduced by 25 percent. The professional component is not reduced.

This matters for the upper-plus-lower scenario. Where both an upper-extremity and a lower-extremity study are performed and documented, 93923 is reported twice, with modifier 59 on the second line to clear the bundling edit. Modifier 59 does that job and nothing more. It does not exempt the second line from the payment reduction, so a practice that budgets for two full studies will see less than it expected on the remittance. The autonomic codes behave differently: both 95921 and 95923 carry a multiple-procedure indicator of 0 and are paid without this reduction.

One related habit to unlearn while you are in the file. The bilateral indicator on 93923 is 2, which means the relative values already assume a bilateral study. Appending modifier 50 to claim a bilateral adjustment on top of that is not correct.

Five errors that generate modifier 26 denials

• Appending modifier 26 when the practice owns the equipment and employs the interpreting physician, which converts a global claim into a partial one.
• Billing modifier 26 against a chart that holds a review note rather than a separate signed interpretive report.
• Appending modifier 26 to a code whose PC/TC indicator does not allow a split.
• Reporting both the global code and a component-modified line for the same study on the same claim.
• Carrying a modifier forward in a billing template after the arrangement behind it has changed, for instance after the practice buys equipment it previously leased time on.

Four of the five are configuration problems rather than clinical ones, which is why they tend to run unnoticed across many claims before anyone catches them. A short audit of how your testing codes are set up in the practice management system usually finds them faster than a claim-by-claim review.

Where HealthWright Technologies fits

HealthWright Technologies sells diagnostic systems to independent physicians, and the practice owns the equipment outright. The CMAT Advantage system runs on-premises in the office, and the report is produced there during the visit, which is what puts the great majority of our partner practices in the global-billing scenario described above. Our role is the device, the training, and the implementation support, along with the coding references our partners ask for. We do not submit claims on a practice’s behalf, and nothing here is legal or coding advice.

For the code-level detail behind the studies themselves, our ABI CPT code 93923 billing guide covers indications, documentation, and diagnosis pairing for extremity arterial studies, and coding the CMAT encounter walks through reporting several codes from a single multi-system test. Autonomic testing has its own conventions, set out in our guide to the autonomic function testing CPT codes. Every one of them ends where this one does: verify against your own Medicare Administrative Contractor’s current policy before you bill.

Frequently asked questions about modifier 26

Does modifier 26 apply if my practice owns the testing equipment?

Generally no. When the practice owns the equipment, employs the staff who perform the study, and employs the physician who interprets it, the service is reported globally with no modifier, and the single payment covers both components. Modifier 26 belongs on a claim only when the professional work and the technical resources come from different entities, or from different Medicare payment localities.

Can I bill modifier 26 and modifier TC on separate lines instead of billing globally?

When one entity furnishes both halves, the expectation is a single global line rather than two component lines. Splitting a service you furnished entirely yourself invites duplicate-billing edits and does not increase payment. Bill the way the arrangement actually works.

Which vascular and autonomic codes can be split with modifier 26?

In the CY2026 fee schedule file, 93923, 95921 and 95923 all carry a PC/TC indicator of 1, so all three have a professional and a technical component available. Indicators are re-published each year, so check the current file rather than relying on a prior year’s answer.

Does modifier 26 change what the documentation has to show?

It raises the visibility of one requirement rather than changing it. Any claim that includes physician work needs a separate signed interpretive report, not a review note. On a modifier 26 claim that report is the entire basis of the claim, so a weak one has nothing else to lean on.

Is the professional component reduced when two studies are done the same day?

No. The diagnostic cardiovascular multiple procedure payment reduction applies to the technical component of the second and each subsequent qualifying study on the same day. The professional component is paid in full, and codes flagged with a multiple-procedure indicator of 0, such as 95921 and 95923, are not reduced at all.

Getting the arrangement and the modifier to match

The modifier 26 question is really a question about your own arrangement, and it takes about ten minutes to answer definitively: identify who owns each device, who performs each study, who signs each interpretation, and then check that the billing template agrees with those three answers. Practices considering in-office testing are usually better served working that through before the equipment arrives rather than after the first remittance.

To talk through how in-office vascular and autonomic testing is set up, staffed and documented in an independent practice, contact HealthWright Technologies at healthwrighttechnologies.com/contact or contact@healthwrighttechnologies.com. Our office is at 60 Bear Creek Marina Road, Mansfield, GA 30055, and the main line is (678) 322-7146.

Disclaimer: This article is for informational purposes only and does not constitute medical, legal, or billing advice. Always consult a qualified healthcare professional for diagnosis, treatment, and clinical decision-making, and confirm coverage and coding with your own Medicare Administrative Contractor.

CPT is a registered trademark of the American Medical Association. All CPT codes and descriptions are copyright the American Medical Association. Code selection is the responsibility of the reporting provider.