CPT Code 93308: Transthoracic Echocardiography (TTE), Limited or Follow-Up Study

What is CPT code 93308?

The CPT code 93308 is used for a limited or follow-up transthoracic echocardiography (TTE) study. This diagnostic test is a focused ultrasound examination of the heart that provides real-time visualization of cardiac structure and function. Unlike comprehensive echocardiography studies or stress echocardiography, code 93308 is used when a limited evaluation is performed to answer a specific clinical question or to follow up on previously identified cardiac findings on potential general or congenital cardiac anomalies.

The 93308 CPT code specifically describes echocardiography, transthoracic, real-time with image documentation (2D), includes M-mode recording, when performed, follow-up, or limited study. This code is appropriate when the examination is focused on particular cardiac structures or functions rather than a complete heart assessment.

A limited TTE (93308) is valuable in numerous clinical scenarios, including:

• Follow-up assessment of previously diagnosed heart valve disorders, such as mitral regurgitation or aortic valve stenosis
• Monitoring changes in ventricular function or ejection fraction in patients with heart failure
• Reassessment of pericardial effusion
• Targeted evaluation of specific cardiac chambers or structures
• Brief reassessment of known congenital heart defects
• Focused evaluation of pulmonary hypertension or other secondary pulmonary hypertension related to left heart disease

The 93308 code includes:

• Two-dimensional (2D) real-time imaging with image documentation
• M-mode recording (when performed)
• Probe placement, image acquisition, and interpretation
• Limited evaluation of cardiac structure and function

While not as comprehensive as a complete TTE, a limited study still requires proper technique and interpretation by qualified healthcare providers. The study often focuses on specific cardiac structures, such as assessment of the mitral and aortic valves, evaluation of a specific cardiac chamber, or measurement of ejection fraction.

CPT code 93308 documentation requirements

Proper documentation supports medical necessity and ensures accurate billing for limited echocardiography studies.

Documentation for a limited TTE (93308) should include:

• Clear documentation of the reason for the limited or follow-up study
• Specific clinical question being addressed
• Reference to previous echocardiography findings when performed as a follow-up study
• Rationale for why a limited study is sufficient rather than a comprehensive evaluation

The Centers for Medicare & Medicaid Services (CMS) emphasizes that medical necessity must be clearly established when billing for limited studies. This typically includes documentation of symptoms, relevant diagnoses, or the need to follow previously identified abnormalities.

Further technical documentation should also include the following to ensure the use of appropriate CPT codes:

• Date and time of the procedures performed
• Name and credentials of the performing sonographer and interpreting physician
• Confirmation that the study was limited in scope (as opposed to complete)
• Specific structures or functions evaluated (e.g., "limited study to assess left ventricular function" or "follow-up evaluation of previously identified pericardial effusion")
• Technical factors such as appropriate probe placement and image acquisition protocols

CPT code 93308 billing guidelines

Understanding the proper billing guidelines for CPT code 93308 is essential for healthcare providers to navigate the reimbursement process successfully.

The 93308 CPT code has specific distinctions that differentiate it from other echocardiography codes:

• It represents a limited or follow-up study, not a comprehensive evaluation
• It does not include spectral Doppler echocardiography or color flow Doppler echocardiography (these would require additional codes)
• It may include M-mode recording when performed, but this is not required for using the code

For accurate billing, it's essential to understand when 93308 is appropriate versus when a more comprehensive code is required.

Like many diagnostic procedures, echocardiography involves both technical and professional components:

• The technical component includes probe placement, image acquisition, and equipment usage
• The professional component involves interpretation and reporting
• The code can be billed globally (both components) or with modifiers to indicate only the professional component or the technical component.

When billing for a limited TTE performed in a hospital setting, the physician typically bills only the professional component with modifier -26, while the facility bills for the technical component.

Other relevant codes

When working with echocardiography services, several related CPT codes may be applicable:

• 93306: Echocardiography, transthoracic, real-time with image documentation (2D), includes M-mode recording, when performed, complete, with spectral Doppler echocardiography, and with color flow Doppler echocardiography
• 93307: Echocardiography, transthoracic, real-time with image documentation (2D), includes M-mode recording, when performed, complete, without spectral or color Doppler echocardiography
• 93320: Doppler echocardiography, pulsed wave and/or continuous wave with spectral display; complete (add-on code)
• 93321: Doppler echocardiography, pulsed wave and/or continuous wave with spectral display; follow up or limited study (add-on code)
• 93325: Doppler echocardiography color flow velocity mapping (add-on code)
• 93350: Echocardiography, transthoracic, real-time with image documentation (2D), includes M-mode recording, when performed, during rest and cardiovascular stress test