If you have ever tried to find the right ankle brachial index test CPT code, you know it can feel a little confusing. You are not alone. Many medical coders, billers, and even healthcare providers mix up the codes for this simple but powerful vascular study.
The good news? Once you understand a few basic rules, choosing the correct code becomes straightforward.
In this guide, we will walk through everything you need to know. From the differences between resting and exercise ABI to documentation tips that keep audits away, consider this your friendly roadmap.
Let us start with the most important answer first.
What Is the Correct CPT Code for Ankle Brachial Index?
The standard CPT code for ankle brachial index testing at rest is CPT 93922. This code covers limited bilateral noninvasive physiologic studies of upper or lower extremity arteries.
However, there is a twist. Depending on how many levels your provider studies and whether they use exercise, the code can change.
Here is the quick breakdown:
| Procedure | CPT Code | What It Includes |
|---|---|---|
| ABI at rest (unilateral or bilateral, limited) | 93922 | One or two levels; ankle pressures and waveforms |
| ABI at rest with more than two levels | 93923 | Complete bilateral study (three or more levels) |
| ABI with exercise (treadmill or plantar flexion) | 93924 | Resting ABI plus post-exercise measurements |
Important note: Do not report 93922 and 93923 together for the same session. Choose the code that best describes the full study performed.
Understanding the Ankle Brachial Index Test (Made Simple)
Before we dive deeper into coding rules, let us quickly review what the ABI test actually does. This will help you understand why coders choose different codes.
The ankle brachial index compares the blood pressure in your ankle to the blood pressure in your arm. It helps diagnose peripheral artery disease (PAD).
Here is how it works:
- A blood pressure cuff is placed on both arms and both ankles.
- A handheld Doppler device listens to blood flow.
- The provider calculates a ratio (ankle pressure divided by arm pressure).
A normal ABI falls between 1.0 and 1.4. Anything below 0.9 suggests PAD.
The test is painless, noninvasive, and takes about 15 to 30 minutes.
CPT 93922: The Most Common Code for ABI
Most routine ABIs performed in an office setting use CPT 93922. This code is officially described as:
“Noninvasive physiologic studies of upper or lower extremity arteries, single level, bilateral (e.g., ankle/brachial indices, Doppler waveform analysis, volume plethysmography, transcutaneous oxygen tension measurement).”
When to Use 93922
You should report 93922 when the provider performs:
- Bilateral ankle brachial indices at rest (one level: the ankle)
- Doppler waveform analysis (optional but often included)
- No more than two levels of study
In plain English: if your provider checks both ankles, compares them to both arms, and stops there, use 93922.
What 93922 Does Not Include
- Segmental pressures (thigh, calf, ankle)
- Exercise testing
- Recording of more than two levels per leg
CPT 93923: Complete Bilateral Study
CPT 93923 is the next step up. Its official descriptor says:
“Noninvasive physiologic studies of upper or lower extremity arteries, three or more levels, bilateral (e.g., segmental blood pressure measurements, segmental Doppler waveform analysis, segmental volume plethysmography, segmental transcutaneous oxygen tension measurement).”
When to Use 93923
Choose 93923 when the provider performs segmental pressures. This means they place cuffs at multiple points on each leg:
- Upper thigh
- Lower thigh or calf
- Ankle
Each of these counts as a level. When you have three or more levels per leg (bilaterally), you move from 93922 to 93923.
Real-World Example
A patient comes in with suspected PAD but no clear symptoms. The provider orders a full segmental study with pressures at the high thigh, calf, and ankle on both legs. That is three levels bilaterally. Use 93923.
CPT 93924: Ankle Brachial Index with Exercise
Sometimes a patient has a normal resting ABI but still reports leg pain with walking. This is where CPT 93924 comes in.
The official descriptor reads:
“Noninvasive physiologic studies of upper or lower extremity arteries, with exercise (e.g., treadmill) prior to and after exercise, bilateral.”
When to Use 93924
Report 93924 when:
- A resting ABI is performed first.
- The patient exercises (usually on a treadmill or via plantar flexion).
- Post-exercise pressures are recorded immediately and at intervals.
Why This Matters
Resting ABIs can miss early or mild PAD. Exercise stresses the circulation and reveals blockages that only appear when muscles demand more blood. So 93924 is not just an add-on—it is a complete study on its own.
Critical coding note: Do not report 93922 or 93923 separately with 93924. The exercise code includes the resting portion.
Side-by-Side Comparison: 93922 vs 93923 vs 93924
Let us make this even clearer. Here is a comparison table you can bookmark.
| Feature | 93922 | 93923 | 93924 |
|---|---|---|---|
| Number of levels | 1-2 | 3 or more | Rest + post-exercise |
| Bilateral required? | Yes | Yes | Yes |
| Includes resting ABI | Yes | Yes | Yes (plus exercise) |
| Segmental pressures | No | Yes | No (unless >2 levels at rest) |
| Exercise | No | No | Yes (treadmill or plantar flexion) |
| Typical setting | Office | Vascular lab | Vascular lab or hospital |
Common Billing Mistakes (And How to Avoid Them)
Even experienced coders slip up sometimes. Here are the most frequent errors with the ankle brachial index test CPT code.
Mistake #1: Using 93922 for a Complete Segmental Study
If your provider documents pressures at three levels (high thigh, calf, ankle) on both legs, you cannot use 93922. That study is more extensive. Use 93923 instead.
Mistake #2: Reporting Both 93922 and 93923 Together
Never report these two codes for the same patient on the same day for the same leg. Choose the one that best matches the documentation.
Mistake #3: Forgetting the Bilateral Requirement
All three codes (93922, 93923, 93924) are bilateral by definition. If the provider only studies one leg, these codes are not correct. In that rare case, you might look at unlisted vascular procedure codes (e.g., 93799), but always check payer policies first.
Mistake #4: Adding a Separate Resting ABI to 93924
As noted above, 93924 includes the resting study. Do not add 93922 or 93923 on top.
Documentation Requirements for ABI Coding
Good documentation is your best friend. It protects you during audits and ensures you get paid correctly.
Here is what every ABI note should include:
- Reason for the test (e.g., leg pain with walking, diabetes with nonhealing ulcer)
- Resting pressures (arm and ankle, both sides)
- Number of levels studied (e.g., “bilateral ankle pressures only” vs. “segmental pressures at thigh, calf, and ankle”)
- Waveform analysis (if performed)
- Exercise protocol (speed, grade, duration, reason for stopping)
- Post-exercise measurements (immediate and every 1-2 minutes until return to baseline)
- Interpretation (normal, borderline, or abnormal)
A Quick Documentation Checklist
- Patient identifiers
- Ordering provider
- Date of service
- Indication
- Technique description
- Pressures recorded (arm + each level per leg)
- Calculated indices
- Signature and credentials
Payer Policies and Reimbursement Tips
Medicare and private payers have specific rules for ABI coding. Here is what you need to know.
Medicare Coverage for ABI
Medicare covers ABI testing for:
- Patients with signs or symptoms of PAD
- Patients with diabetes and a nonhealing wound
- Preoperative evaluation for lower extremity revascularization
Medicare does not cover screening ABIs for asymptomatic patients without risk factors.
LCDs (Local Coverage Determinations)
Always check your local MAC’s LCD. Some regions have specific requirements for the number of waveform recordings or the need for segmental pressures before approving 93923.
Reimbursement Rates (Approximate)
Rates vary by region and payer. But as a rough guide (2024-2025 averages):
| CPT Code | Facility Rate | Non-Facility Rate |
|---|---|---|
| 93922 | 60–80 | 110–140 |
| 93923 | 120–150 | 180–220 |
| 93924 | 150–190 | 230–280 |
These are estimates. Always verify with your specific fee schedule.
When to Add Modifiers
Modifiers are not common with ABI codes, but there are exceptions.
Modifier 59 (Distinct Procedural Service)
Use modifier 59 if:
- The ABI is performed on a different extremity than another vascular study on the same day.
- The ABI is performed for a completely different reason than another procedure.
Example: A patient has a carotid duplex (ultrasound) and a separate ABI on the same day. Append modifier 59 to the ABI code if the documentation supports distinct sessions.
Modifier LT or RT
Remember that ABI codes are bilateral. So you generally do not use LT or RT modifiers. If a payer ever asks you to bill for one leg only (rare), check their specific guidance.
ABI vs. Other Vascular Tests: A Quick Reference
Sometimes coders confuse ABI with other noninvasive vascular studies. Here is a simple cheat sheet.
| Test | CPT Code(s) | What It Measures |
|---|---|---|
| Ankle Brachial Index (limited) | 93922 | Pressures at ankle level only |
| Segmental pressures with waveforms | 93923 | Pressures at multiple levels (thigh to ankle) |
| ABI with exercise | 93924 | Resting + post-exercise pressures |
| Arterial duplex (ultrasound) | 93925, 93926 | Imaging of arteries with Doppler |
| Toe brachial index (TBI) | 93922 (if limited) or unlisted | Pressure at toe level |
Note on TBI: Toe brachial index is often bundled into 93922 if performed in addition to ABI. Some payers accept 93922 for TBI alone. Others require an unlisted code. Check first.
Real-World Scenarios (With Correct Codes)
Let us walk through some patient cases. This will help you apply the rules in practice.
Scenario 1: Routine PAD Screening
Patient: 65-year-old with diabetes and a history of smoking. No leg pain. Provider orders bilateral ankle pressures with Doppler waveforms.
Documentation: Pressures: right arm 130, left arm 128, right ankle 118, left ankle 112. Indices: 0.91 and 0.88. No segmental pressures.
Correct code: 93922
Scenario 2: Symptomatic Patient with Normal Resting ABI
Patient: 58-year-old with calf pain after walking two blocks. Resting ABI is 1.05 bilaterally. Provider orders treadmill exercise at 2 mph, 10% grade for 5 minutes until pain. Post-exercise ABI drops to 0.75 on the right.
Correct code: 93924
Scenario 3: Complete Segmental Study for Nonhealing Ulcer
Patient: 72-year-old with a toe ulcer. Provider orders pressures at high thigh, above knee, below knee, and ankle on both legs.
Documentation: Four levels per leg. All pressures recorded. Waveforms analyzed.
Correct code: 93923
Scenario 4: Unilateral Study (Rare)
Patient: Right above-knee amputation. Left leg only studied with segmental pressures at three levels.
Documentation: Unilateral study clearly stated.
Correct code: This is a gray area. Most payers expect bilateral for 93923. Some accept 93923 with modifier 52 (reduced services). Others require an unlisted code (93799). Best practice: Call the payer or check their LCD.
How to Improve ABI Documentation in Your Practice
Good documentation starts with the provider. But as a coder or biller, you can gently guide them.
Tips for Talking to Providers
- Ask them to specify “bilateral ankle pressures only” or “segmental pressures with three levels” in their note.
- Encourage them to note “no exercise performed” or “exercise performed per protocol.”
- Remind them that waveform analysis must be documented to support the higher-level codes.
A Simple Template for Providers
“Bilateral noninvasive physiologic study of lower extremity arteries performed. Resting brachial pressures: R ___, L ___. Segmental pressures recorded at high thigh, calf, and ankle bilaterally. Doppler waveforms analyzed at each level. ABI indices calculated. No exercise performed. Interpretation: Normal/Abnormal.”
That single paragraph supports 93923 beautifully.
Medicare’s NCCI Edits and ABI Coding
The National Correct Coding Initiative (NCCI) prevents unbundling. Here is what you need to know.
Do Not Report Together
- 93922 and 93923 on the same leg same day
- 93922 or 93923 with 93924 on the same leg same day
- ABI codes with a separate E/M service unless modifier 25 is appended to the E/M
E/M with ABI (Modifier 25)
If the provider sees the patient for a separate, identifiable evaluation and management service on the same day as the ABI, append modifier 25 to the E/M code. The ABI code does not need a modifier.
Example: New patient visit (99204) for leg pain. Provider decides to perform an ABI (93922) during the same encounter. Bill 99204-25 and 93922.
Private Payer Variations
Not all payers follow Medicare rules. Some commercial plans have different policies.
Common Private Payer Differences
- UnitedHealthcare: May require prior authorization for 93924.
- Aetna: Considers 93922 and 93923 as bundled into certain vascular surgery codes.
- Cigna: Sometimes covers screening ABIs for high-risk patients (unlike Medicare).
Always verify with the specific plan. Do not assume.
Frequently Asked Questions (FAQ)
1. Can I bill 93922 for a unilateral ABI?
Technically, no. The code descriptor says “bilateral.” However, some coders report it with modifier 52 (reduced services). A safer approach is to check payer policy or use an unlisted code.
2. Is there a separate CPT code for toe brachial index (TBI)?
No standalone CPT code exists for TBI. Most coders use 93922 if only the toe and arm are compared. But some payers prefer an unlisted code. Document clearly.
3. What is the difference between 93922 and 93923 in plain English?
93922 = ankle pressures only.
93923 = thigh, calf, and ankle pressures (segmental).
4. Does 93924 require a treadmill every time?
No. Some patients cannot walk on a treadmill. In those cases, plantar flexion (repeated toe raises) is acceptable. Document the exercise protocol.
5. Can an ABI be performed by a technician?
Yes. But the interpretation must be performed by a qualified provider (physician, nurse practitioner, or physician assistant, depending on state law and payer rules).
6. How often can I bill an ABI for the same patient?
Medicare typically covers ABI once per year for stable patients. More frequent testing requires documented clinical necessity (e.g., change in symptoms, post-intervention follow-up).
7. What ICD-10 codes support medical necessity for ABI?
Common codes include:
- I73.9 (Peripheral vascular disease, unspecified)
- R02.03 (Gangrene, lower extremity)
- E11.51 (Type 2 diabetes with peripheral circulatory disorder)
- M79.60 (Pain in limb, unspecified)
8. Is ABI the same as a vascular screening?
No. A screening is performed without signs or symptoms. Medicare does not cover screening ABIs. Diagnostic ABIs (with symptoms or risk factors) are covered.
9. What happens if I use the wrong code?
You risk denial, audit flags, or potential overpayment recoupment. If you realize you used the wrong code, file a corrected claim as soon as possible.
10. Where can I find official CPT guidelines for 93922-93924?
The AMA’s CPT Professional Edition is the official source. Medicare’s NCCI manual also provides helpful guidance.
Additional Resource
For the most current Medicare payment policies and Local Coverage Determinations (LCDs) for vascular testing, visit the CMS Coverage Database:
🔗 https://www.cms.gov/medicare-coverage-database/
Search for “Ankle Brachial Index” or “Noninvasive Physiologic Studies” in your state or MAC region.
Key Takeaways (Before You Go)
- The primary ankle brachial index test CPT code for routine resting studies is 93922.
- Use 93923 for segmental pressures at three or more levels bilaterally.
- Use 93924 when exercise is performed before and after resting pressures.
- Never report 93922 and 93923 together.
- Always document the number of levels, exercise status, and waveforms.
- Check your local MAC’s LCD for region-specific rules.
Conclusion
The ankle brachial index test CPT code is not as complicated as it first appears. Choose 93922 for simple bilateral ankle pressures. Switch to 93923 for segmental studies with three or more levels. And reach for 93924 when exercise is part of the protocol. Keep your documentation clear, follow payer policies, and you will code with confidence every time.
Disclaimer: This article is for educational purposes only. CPT codes and payer policies change frequently. Always verify current coding guidelines with the AMA, CMS, and your specific payer contracts. This content does not constitute legal or medical advice.
