TM Flow CPT Code

Understand TM Flow CPT Code: A Comprehensive Billing Guide

The TM Flow System, which provides a non-invasive method of evaluating vascular health and autonomic nervous system function, has become a useful tool for modern medical treatments. However, understanding medical billing codes, particularly for a relatively new technology like TM Flow, can be confusing. This blog explains TM Flow CPT codes, providing a clear and concise guide for healthcare providers and their billing staff.

Why are TM Flow CPT Code Important?

The US has a standardized system for medical billing called CPT (Current Procedural Terminology) codes. These codes specify particular medical treatments and services, allowing insurance companies to properly repay. It’s important to understand the right TM Flow Test CPT code to guarantee correct invoicing and fair recompense for completing the test.

What is a TM Flow Test & What Does it Measure?

Before discussing further you must be wondering, what does TM flow stands for? TM Flow stands for Transonic Multispectral Flow. It’s a non-invasive diagnostic technology that measures different physiological parameters with a finger sensor.

These variables, which include sweat gland activity, blood flow, and temperature, offer important information on the current condition of the autonomic nervous system and peripheral circulation.

Does TM Flow Have a Dedicated CPT Code?

There is currently no single, specific CPT code for TM Flow System itself. This is because the TM Flow system gathers data for various assessments, each potentially falling under different CPT code categories.

Understanding Applicable CPT Codes for TM Flow Tests:

Depending on the specific TM Flow test performed, there are relevant CPT codes for billing purposes. Here’s a breakdown of the most commonly used codes:

  • 95921 

Evaluation of the Autonomic Nervous System (ANS) by Quantitative Sudomotor Activity (QSART): This code is used when the TM Flow test is primarily used to assess sweat gland function, which is a key indicator of ANS health.

  • 95923 

Sudomotor Axon Reflex Test (SART): This code applies when the TM Flow test focuses on evaluating the integrity of the sympathetic cholinergic pathway, another vital component of the ANS.

  • 93922 

Ankle-Brachial Index (ABI): This code is relevant when the TM Flow test is used to measure ABI, a non-invasive method for assessing peripheral arterial disease (PAD). 

Important Billing Considerations

  • Multiple Tests, Multiple Codes

If the TM Flow test incorporates assessments covered by different CPT codes (e.g., evaluating both ANS function and ABI), you can bill for each applicable code. However, remember to use appropriate modifiers to indicate multiple procedures performed during the same encounter.

  • Physician Interpretation 

A licensed medical professional is required to diagnose patients based on the data generated by the TM Flow technology. It is possible to bill an Evaluation and Management (E/M) code in addition to the TM Flow test code; however, you must use the relevant 25 modifier to show that the E/M service was provided along with the test.

  • Accuracy Is Essential 

For correct payment, it’s necessary to use the most accurate CPT code for the particular TM Flow test that was conducted. By consulting with a skilled healthcare billing specialist, you can make sure you are using the right codes and optimizing the income from your clinic.

Considerations for TM Flow Billing

While the above provides a general framework, here are some additional factors to consider for accurate TM Flow billing:

  • Consult your Specific Payer 

Insurance companies may have their own guidelines for TM Flow billing. It’s always best to consult your specific payer for the most up-to-date information.

  • Bundled Codes

Certain CPT codes might be bundled together, meaning you can only bill for one code encompassing multiple services. Be mindful of potential bundling rules related to the chosen CPT code.

  • Modifiers 

In specific situations, modifiers might be necessary to further clarify the details of the TM Flow test performed. Consult your coding manual or a healthcare billing expert for guidance on appropriate modifiers.

Additional Billing Tips

While understanding TM Flow CPT codes is crucial, effective billing involves more than just codes. Here are some additional tips to ensure smooth reimbursement:

  • Accurate Documentation: 

Maintain detailed medical records documenting the rationale for the TM Flow test, the specific test performed (e.g., autonomic function or vascular health), and the results.

  • Clear Communication

Communicate effectively with patients about the test and potential associated costs.

  • Stay Updated

Periodically, CPT codes and billing criteria may vary. Reliable sources such as the website of the American Medical Association (AMA) or consulting with a medical billing specialist will help you stay informed.


The TM Flow System offers a valuable addition to the diagnostic toolkit for healthcare providers. Understanding the applicable TM Flow CPT codes ensures accurate billing and helps you maximize reimbursement for utilizing this innovative technology. By staying informed about billing procedures and effectively communicating with patients, healthcare providers can use the TM Flow system to enhance patient care and optimize their practice’s operation.


  1. Is there a single CPT code for all TM Flow tests?

No, there is not a single CPT code for the TM Flow System itself. The specific test performed using the system determines the appropriate code. Codes like 95921 (QSART), 95923 (SART), and 93922 (ABI) might apply depending on the focus of the evaluation (ANS function, sweat gland activity, or peripheral arterial disease).

  1. Can I bill for multiple TM Flow tests during the same encounter?

Yes, if the TM Flow test incorporates assessments covered by different CPT codes, you can bill for each applicable code. Remember to use the appropriate modifier to indicate these are additional services performed within the same visit.

  1. Do I need to bill an E/M code alongside the TM Flow CPT code?

You can potentially bill for an E/M (Evaluation and Management) service in conjunction with the TM Flow test code. However, ensure proper documentation justifies the additional E/M service and utilize the appropriate modifier (e.g., 25 modifier) to signify it was provided with the test.

  1. Where can I find the latest information on TM Flow billing guidelines?

It’s best to consult reliable resources like the American Medical Association (AMA) website or your specific insurance provider for the most up-to-date information on TM Flow billing guidelines. Codes and regulations can change periodically.

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