How To Use CPT Code 94729

CPT 94729 is a code used for diffusing capacity testing, specifically for measuring the lungs’ ability to exchange gases. This article will cover the description, procedure, qualifying circumstances, appropriate usage, documentation requirements, billing guidelines, historical information, similar codes, and examples of CPT 94729 procedures.

1. What is CPT 94729?

CPT 94729 is a code used in the Current Procedural Terminology (CPT) system to represent a specific medical procedure, which is the diffusing capacity testing of the lungs. This test measures the ability of the lungs to exchange gases, such as oxygen and carbon dioxide, between the bloodstream and the lungs. It is an essential diagnostic tool for healthcare providers to assess lung function in patients with various lung conditions, such as lung cancer or emphysema.

2. 94729 CPT code description

The official description of CPT code 94729 is: “Diffusing capacity (e.g., carbon monoxide, membrane) (List separately in addition to code for primary procedure)”.

3. Procedure

The procedure for CPT 94729 involves the following steps:

1. The patient’s nose is clipped to ensure they only breathe through their mouth during the test.
2. The patient inhales a small amount of tracer gas, which is typically carbon monoxide.
3. The patient holds their breath for a few seconds, allowing the tracer gas to diffuse across the lung membranes.
4. The patient exhales quickly into a mouthpiece, which collects the exhaled breath for analysis.
5. The concentration of the tracer gas in the exhaled breath is measured, which is proportional to the lung’s diffusing capacity.
6. The interpreting provider checks the results for errors, reviews the data and testing procedure, interprets the results, and records the interpretation in the patient’s medical record.

4. Qualifying circumstances

Patients who are eligible to receive CPT code 94729 services are those with lung conditions that may affect their lung function, such as lung cancer, emphysema, or other respiratory diseases. The test may also be used for patients with unexplained shortness of breath or other respiratory symptoms, as well as for monitoring the progress of lung disease treatment or evaluating lung function before surgery.

5. When to use CPT code 94729

It is appropriate to bill the 94729 CPT code when the diffusing capacity test is performed during the same session as other pulmonary function testing. The test should be billed as an add-on code, in conjunction with the primary code for pulmonary testing, which includes codes 94010, 94060, 94070, 94375, 94726 to 94728.

6. Documentation requirements

To support a claim for CPT 94729, the following information should be documented:

• The patient’s medical history, including any relevant lung conditions or respiratory symptoms.
• The reason for performing the diffusing capacity test, such as diagnosing or monitoring a lung condition, or evaluating lung function before surgery.
• A detailed description of the testing procedure, including the tracer gas used, the patient’s breathing technique, and the collection of exhaled breath for analysis.
• The results of the test, including the concentration of the tracer gas in the exhaled breath and the calculated diffusing capacity of the lungs.
• The interpreting provider’s review and interpretation of the test results, as well as any recommendations for further testing or treatment.

7. Billing guidelines

When billing for CPT code 94729, it is important to follow these guidelines:

• Report the code as an add-on code, in conjunction with the appropriate primary code for pulmonary testing (94010, 94060, 94070, 94375, 94726 to 94728).
• If reporting only the professional component of the service, append modifier 26 to the code.
• If reporting only the technical component of the service, append modifier TC to the code, unless the hospital provided the technical component. In that case, do not append modifier TC, as the hospital’s portion is inherently technical.
• Do not append a professional or technical modifier to the code when reporting a global service in which one provider renders both the professional and technical components.

8. Historical information

CPT 94729 was added to the Current Procedural Terminology system on January 1, 2012. There have been no updates to the code since its addition.

9. Similar codes to CPT 94729

Five similar codes to CPT 94729 and how they differ are:

• CPT 94726: Measures lung volumes using plethysmography, a different method of assessing lung function.
• CPT 94727: Measures lung volumes using gas dilution or washout, another alternative method for assessing lung function.
• CPT 94728: Measures lung volumes using multiple-breath nitrogen washout, a specific gas dilution technique.
• CPT 94010: Represents a basic spirometry test, which measures the amount and speed of air a patient can inhale and exhale.
• CPT 94060: Represents a bronchodilation responsiveness test, which assesses the patient’s response to medication that opens the airways.

10. Examples

Here are 10 detailed examples of CPT code 94729 procedures:

1. A patient with a history of emphysema undergoes a diffusing capacity test to monitor the progression of their lung disease.
2. A patient with lung cancer has a diffusing capacity test to evaluate their lung function before undergoing surgery.
3. A patient with unexplained shortness of breath undergoes a diffusing capacity test to help determine the cause of their symptoms.
4. A patient with chronic obstructive pulmonary disease (COPD) has a diffusing capacity test to assess the severity of their condition.
5. A patient with a history of smoking undergoes a diffusing capacity test as part of a comprehensive pulmonary function evaluation.
6. A patient with asthma has a diffusing capacity test to assess their lung function and response to treatment.
7. A patient with interstitial lung disease undergoes a diffusing capacity test to monitor the effectiveness of their treatment regimen.
8. A patient with sarcoidosis has a diffusing capacity test to evaluate the extent of lung involvement in their condition.
9. A patient with pulmonary fibrosis undergoes a diffusing capacity test to assess the progression of their lung disease.
10. A patient with a history of exposure to occupational lung hazards has a diffusing capacity test as part of a routine lung health assessment.