Cardiology Coding Alert

Make sure you follow the ABI guidelines to the letter.

Last month, in the article “Look to This Guidance to Improve Your Peripheral Artery Disease Coding,” in Cardiology Coding Alert Volume 27, Issue 6, you learned all about the signs and symptoms of peripheral artery disease (PAD) and which ICD-10-CM codes you should report for this condition.

Now, see what Elizabeth Herbert, RHIA, CPC, CDEO, CPMA, CRC, CCC, AAPC Approved Instructor, had to say about the ankle-brachial index (ABI), which is a testing option for peripheral artery disease (PAD), in her HEALTHCON 2024 session “Peripheral Artery Disease: Diagnostics and Treatments of the Lower Extremities.”

Editor’s note: Stay tuned for next month to discover even more diagnostic testing options for PAD.

Comprehend Why Physicians Perform ABI

“The ABI is a ratio that compares brachial and ankle pressures,” Herbert said. “First, they take the bilateral systolic blood pressure. Then they measure it at the ankle with the anterior tibial and posterior tibial arteries. Typically they’ll do one or more levels in the leg— either the ankle, calf, or thigh — and then compare that resulting ratio.”

The resulting ratio can let the physician know if the patient has PAD and how severe it is, she added.

“Just doing that ratio alone is not reimbursable by itself; they could do that in the office during an evaluation and management (E/M) visit, Hebert said. “But if they perform the ABI along with other non-invasive measurements, we can code and bill it.”

Examples of these other non-invasive measurements that a physician can perform along with an ABI include the following:

• Segmental Blood Pressure Measurements
• Pulse Volume Recordings (PVRs)
• Continuous Wave Doppler Waveforms
• Transcutaneous Oximetry Measurement
• Toe-brachial indices (TBIs)

Take a look at this chart to see what the ABI readings mean:

Don’t miss: Limitations for ABIs include if the patient has medial arterial calcification, also known as Monckeberg’s arteriosclerosis. Herbert said. Also, aortoiliac disease may cause normal or borderline rest ABIs.

A low, or less than 0.9 ratio, would indicate PAD, and the physician could classify that as mild, moderate, or severe, Herbert said. If the index is borderline or normal, but the physician suspects PAD, they can do the index again after exercise stress testing to see if that makes a difference.

Delve Into ABI Testing Codes

You have three codes for ABI testing according to Herbert. They include the following:

Option 1: 93922 (Limited bilateral noninvasive physiologic studies of upper or lower extremity arteries, (eg, for lower extremity: ankle/brachial indices at distal posterior tibial and anterior tibial/dorsalis pedis arteries plus bidirectional, Doppler waveform recording and analysis at 1-2 levels, or ankle/brachial indices at distal posterior tibial and anterior tibial/dorsalis pedis arteries plus volume plethysmography at 1-2 levels, or ankle/brachial indices at distal posterior tibial and anterior tibial/dorsalis pedis arteries with, transcutaneous oxygen tension measurement at 1-2 levels).

Code 93922 is labeled as limited bilateral, and it indicates one to two levels tested, Herbert said. The limited test includes the ABI ratio, and then they can do one to two levels of measurement of one of the following:

• Bidirectional Doppler Waveform recording and analysis
• Volume Plethysmography
• Transcutaneous Oxygen Tension Measurement

Option 2: 93923 (Complete bilateral noninvasive physiologic studies of upper or lower extremity arteries, 3 or more levels (eg, for lower extremity: ankle/brachial indices at distal posterior tibial and anterior tibial/dorsalis pedis arteries plus segmental blood pressure measurements with bidirectional Doppler waveform recording and analysis, at 3 or more levels, or ankle/brachial indices at distal posterior tibial and anterior tibial/dorsalis pedis arteries plus segmental volume plethysmography at 3 or more levels, or ankle/brachial indices at distal posterior tibial and anterior tibial/dorsalis pedis arteries plus segmental transcutaneous oxygen tension measurements at 3 or more levels), or single level study with provocative functional maneuvers (eg, measurements with postural provocative tests, or measurements with reactive hyperemia))

Code 93923 is a complete bilateral test, Herbert added. This includes the ABI ratio and three or more levels of these tests — Bidirectional Doppler Waveform recording and analysis; Volume Plethysmography; or Transcutaneous Oxygen Tension Measurement. Or the physician can perform a single level with provocative functional maneuvers.

Option 3: 93924 (Noninvasive physiologic studies of lower extremity arteries, at rest and following treadmill stress testing, (ie, bidirectional Doppler waveform or volume plethysmography recording and analysis at rest with ankle/brachial indices immediately after and at timed intervals following performance of a standardized protocol on a motorized treadmill plus recording of time of onset of claudication or other symptoms, maximal walking time, and time to recovery) complete bilateral study)

Code 93924 is a complete bilateral study done at rest and following treadmill stress testing, Herbert said. This test includes the ABI ratio and Bidirectional Doppler Waveform recording and analysis or Volume Plethysmography performed at rest and immediately after and at timed intervals following standardized protocol on a treadmill.

Some of the levels you will see on ABIs include high thigh, low thigh, calf, ankle, metatarsals, or toes, Herbert said.

Follow These ABI Guidelines

You must follow specific rules when reporting ABIs, Herbert said.

First, all of these codes are already labeled as bilateral, so when the physician performs a unilateral study, we must alter the codes for the billing, according to Herbert.

For example, when the physician performs a unilateral study for one to two levels, report 93922 with modifier 52 (Reduced services) appended.

However, when the physician performs a unilateral study for three or more levels report 93922 with no modifier.

Also, Herbert added that you can report 93922 or 93923 only once in the upper extremities and/or once in the lower extremities. When the physician evaluates both the upper and lower extremities in the same setting, you can report 93922 or 93933 twice by adding modifier 59 (Distinct procedural service) to the second procedure.

Never report 93924 with 93922 or 93923.

Lastly, since the ABIs are global services, use modifier TC (Technical component) or modifier 26 (Professional component) when appropriate, Herbert said.