CPT code 93924 – Lower extremity arterial study with treadmill stress

Key takeaways

CPT code 93924 reports a complete bilateral lower extremity arterial study at rest and after a standardized treadmill test.

Ankle-brachial indices are part of 93922, 93923 and 93924, so the treadmill sets 93924 apart, not the ABI.

A complete resting study without treadmill stress is 93923, and billing it as 93924 is a denial and audit risk.

93924 is already bilateral, so leave off modifier 50 and LT/RT, and don’t report 93922 or 93923 alongside it.

Medicare’s CY2026 national non-facility payment is about $165, based on 4.95 total RVUs and global indicator XXX.

CPT code 93924 is the treadmill version of the leg arterial study

CPT code 93924 reports a noninvasive physiologic study of the lower extremity arteries, at rest and following treadmill stress testing. It is a complete bilateral study, so both legs are always included.

The American Medical Association (AMA) descriptor sets out what the study must contain:

• Bidirectional Doppler waveform or volume plethysmography recording and analysis at rest.
• Ankle/brachial indices immediately after a standardized protocol on a motorized treadmill.
• Repeat ankle/brachial indices at timed intervals as the patient recovers.
• The time to onset of claudication or other symptoms, the maximal walking time, and the time to recovery.

The code sits in the Medicine section, under noninvasive vascular diagnostic studies (93880-93998). Within that range, it belongs to the extremity arterial studies group, 93922-93931.

Physicians order it to unmask peripheral arterial disease (PAD) that looks mild at rest. A patient with claudication can have a near-normal resting ABI. Walking drops the ankle pressure, and the post-exercise values reveal it.

What happens during a 93924 study, step by step

A 93924 session runs in a fixed order. Each step leaves a value the report needs.

1. Resting baseline. The technologist records Doppler waveforms or volume plethysmography in both legs, plus resting ankle and brachial pressures.
2. Treadmill protocol. The patient walks a standardized protocol on a motorized treadmill. The lab’s protocol sets the speed, grade and maximum duration.
3. Symptom timing. Staff note when claudication or other symptoms start, and how long the patient walks in total.
4. Post-exercise ABIs. Ankle/brachial indices are measured right after walking, then again at timed intervals.
5. Recovery. The record shows how long pressures take to return to baseline.
6. Interpretation. A qualified physician reviews the data and signs the final report.

If the treadmill step never happens, the session is not a 93924. The next section shows where it lands instead.

93924 vs 93922 vs 93923: The treadmill decides

All three codes include ankle/brachial indices, so the ABI can’t be the dividing line. What changes is the number of levels, the limbs studied, and whether a treadmill is used.

Two rules follow from the table. A complete resting study of both legs is 93923, however thorough it is. Reactive hyperemia is a provocative maneuver under 93923, so it can’t stand in for the treadmill.

Billing 93924 without documented treadmill stress is a denial and audit risk. Reviewers read the report against the descriptor, and a missing exercise protocol fails it.

The decision path below puts those checks in the order a coder should run them.

Related vascular codes to know

• 93925: Duplex scan of lower extremity arteries or arterial bypass grafts, complete bilateral study. It uses B-mode imaging plus Doppler, a different method from the pressure-based 93924.
• 93926: The same lower extremity arterial duplex scan, as a unilateral or limited study.
• 93880: Duplex scan of extracranial arteries, complete bilateral study. It appears when carotid disease is assessed alongside PAD.
• 93970: Duplex scan of extremity veins, complete bilateral study. It answers venous questions such as deep vein thrombosis, not arterial ones.

A worked example: One patient, two possible codes

Take a hypothetical patient who reports calf pain after walking two blocks. The physician orders a lower extremity arterial study.

Version A. The lab records waveforms and pressures at four levels in each leg, with ABIs at rest. Nobody walks on a treadmill. That is a complete bilateral resting study, so the claim goes out as 93923.

Version B. The lab runs the same resting study, then adds a standardized treadmill walk. Symptoms start at two minutes, and the patient stops at four. ABIs are repeated right after walking and at timed intervals until pressures recover. Now 93924 fits, and only 93924 is billed.

The patient and the diagnosis are identical in both versions. The documented treadmill protocol is the only reason the code changes.

What Medicare pays for CPT code 93924 in 2026

Under the CMS Physician Fee Schedule for calendar year (CY) 2026, 93924 carries 4.95 total relative value units (RVUs). The conversion factor turns those units into dollars.

These national figures come from the CMS CY2026 relative value file. The global amount applies when one provider owns the equipment and reads the study, as in an office or independent lab.

In a hospital outpatient department, the physician bills modifier 26 and the hospital is paid separately for the technical side. Check the 26 and TC amounts for your locality in the CMS Physician Fee Schedule lookup tool.

Rates change every January and vary by locality, so update fee sheets each year. Medicaid programs and commercial payers set their own rates.

Diagnosis codes that support a 93924 claim

Medical necessity rides on the right ICD-10-CM code. Your Medicare Administrative Contractor’s LCD and its billing article list the covered diagnoses. Commercial payers publish their own policies, so check both.

Code the most specific diagnosis the record supports. Coverage lists are updated, so confirm the current LCD version against the CMS ICD-10 resources before you rely on a code.

Modifiers on 93924 are mostly about what to leave off

Most modifier errors on this code come from forgetting that it already covers both legs.

• 26 (professional component): The interpreting physician bills the read and report only. This is common in hospital outpatient settings.
• TC (technical component): The facility or lab bills the equipment, supplies and technologist time.
• Modifier 50 (bilateral): Leave it off. 93924 already describes both legs, so modifier 50 reads as a duplicate service.
• LT and RT: Leave them off. Laterality modifiers suggest a one-sided study and invite review.
• 59 or an X modifier: Use only for a distinct service, where the NCCI modifier indicator allows a bypass and the record supports it.

How a 93924 claim moves, and where it trips

A 93924 claim passes through several hands before payment. Each handoff has its own failure point.

1. Order. The referring provider documents why the study is needed. It trips when the order lists no symptoms or findings.
2. Coverage check. The front desk runs insurance eligibility verification and any prior authorization. It trips when a plan needs auth that nobody requested.
3. Study. The lab runs the resting and treadmill phases. It trips when the patient can’t walk, which turns the session into a 93923.
4. Report. The physician interprets and signs. It trips when post-exercise ABIs stay on the technologist’s worksheet.
5. Coding. The coder picks the code and modifiers. It trips when 93923 is added for the same legs, or modifier 50 slips on.
6. Submission. The claim goes to the payer through a clearinghouse. It trips on eligibility or payer ID rejections.
7. Adjudication. The payer runs NCCI edits and LCD diagnosis checks. It trips on an uncovered ICD-10-CM code.

Catch these before submission and you send a clean claim the first time.

Common mistakes that get 93924 denied

Most 93924 denials repeat the same handful of patterns. Here is each one with its fix.

Track which row your denials fall into each month. That pattern shows where your denial management effort should go first.

Before you submit: A 93924 documentation checklist

Run through this list before the claim leaves the practice. A superbill built around these fields makes the check routine.

• A clinical indication from the ordering provider, such as claudication with a walking distance.
• Resting Doppler waveforms or volume plethysmography for both legs.
• Resting ankle and brachial pressures, with an ABI calculated for each leg.
• The treadmill protocol used, including speed, grade and duration.
• Time to symptom onset, maximal walking time and time to recovery.
• ABIs immediately after exercise and at each timed interval.
• A signed interpretation with findings and a clinical impression.

If any treadmill item is missing, stop and recheck the code. A complete resting study may still qualify as 93923. Holding claims until the report is signed is part of basic medical billing compliance.

Same-day coding: NCCI edits and the XXX indicator

National Correct Coding Initiative (NCCI) edits bundle 93922 and 93923 into 93924. For the same legs in the same session, report 93924 only.

Every edit pair carries a modifier indicator. Check the current CMS NCCI table before you append 59 or an X modifier, because some pairs never allow a bypass.

93925 is a duplex scan, which is a different technology. When both studies are ordered, performed and documented separately, check the current edit pair and payer policy before billing them together.

On the fee schedule, 93924 carries global indicator XXX. That means the global surgery concept doesn’t apply, so no global period bundles same-day services into it. A same-day visit still needs its own documentation and any modifier an edit requires.

Prior authorization for 93924 depends on the plan

Traditional Medicare doesn’t usually require prior authorization for 93924. Instead, it relies on the LCD’s medical necessity rules and post-payment review.

Medicare Advantage and commercial plans often do require it, and their rules change by plan year. Approval usually rests on criteria like these:

• Documented claudication, rest pain or tissue loss in the legs.
• Abnormal findings on exam, such as weak or absent pedal pulses.
• Vascular mapping before a planned intervention.
• Surveillance after a revascularization.

How Pabau keeps 93924 claims moving after submission

Once the study is coded, the next risk is a claim that stalls without anyone noticing. Someone has to send it, watch it, and act on the response.

Pabau, the practice management platform we build, submits claims electronically through clearinghouse integrations. For US practices, that clearinghouse is Claim.MD.

Each claim’s status stays in one view, so claims management gets faster for your billing team. They see a rejection early, fix the cause, and resubmit before the follow-up deadline passes.

Track every 93924 claim to payment

Pabau submits claims electronically through its clearinghouse integrations and tracks each one. Your team spots a rejected vascular study claim early and resubmits it faster.

Book a demo

Conclusion

Code 93924 from the signed report, not from the order. If the report shows both legs, a standardized treadmill protocol and timed post-exercise ABIs, bill 93924 alone. If it shows a thorough resting study, bill 93923 instead.

That single check removes the biggest audit exposure on this code. The remaining fixes are mechanical: no modifier 50, no lower-level code alongside it, and a diagnosis your LCD covers.

After that, tracking the claim matters as much as coding it. Book a demo to see how Pabau sends and tracks vascular study claims through to payment.

Continue your research

Curious how claims travel from your system to the payer? Claim.MD clearinghouse overview explains how CPT claims route through a clearinghouse before they reach the payer.

Want fewer 93924 claims bounced back for missing details? Superbill best practices covers the fields and sign-off steps behind clean vascular study billing.

Looking for the 837P transaction details behind vascular claims? Understanding 837 claim files breaks down the electronic format used to submit CPT 93924 claims.

Need the limited version of this study? CPT code 93922 covers the bilateral arterial study at 1-2 levels, with no treadmill stress.

Frequently asked questions