CPT code 93306 is one of the main echocardiography codes used in cardiology billing. It applies to a complete transthoracic echocardiogram, often called a TTE, when the study includes 2D imaging, M-mode when performed, spectral Doppler, and color flow Doppler. For billing teams, the risk is not usually the code definition.
The risk is proving that the study was complete, medically necessary, and reported with the correct component or modifier. CPT codes describe medical services and procedures for reporting and payment, and the American Medical Association maintains the CPT code set used across U.S. healthcare billing.
What is CPT Code 93306?
CPT code 93306 is used for a complete transthoracic echocardiography study performed through the chest wall. The test uses ultrasound to evaluate heart structures and function. AAPC describes the service as 2D imaging through the chest wall, with evaluation of the four heart chambers, heart valves, adjacent aorta, and heart wall. The service may include both a professional component and a technical component, depending on who performs and bills each part.
It is different from a limited echo code because the provider is not checking only one narrow issue. It is also different from a complete TTE without Doppler because 93306 includes Doppler work as part of the reported service. CMS states that for dates of service on or after January 1, 2009, code 93306 should be used when Doppler is combined with a complete echocardiogram.
What a Complete TTE Should Include?
A complete transthoracic echocardiogram is more than a quick ultrasound view of the heart. It should show that the study evaluated the needed cardiac structures and produced image documentation that supports the final interpretation.
ASE guidance also supports documenting standard views, measurements, Doppler findings, and report details for a complete adult TTE.
2D Imaging and M-mode
2D imaging supports chamber, valve, wall-motion, and structural assessment. M-mode, when performed, records motion along a single ultrasound line and may be used for certain measurements. Since the code says M-mode is included when performed, the report should not imply that M-mode is required in every case, but it should clearly document it when used.
Spectral Doppler and Color Flow Doppler
Doppler findings matter because they support the use of 93306 instead of a code for a complete study without Doppler. Spectral Doppler measures blood-flow velocity and direction across structures. Color flow Doppler maps blood-flow patterns on the image. CMS coverage language states that spectral Doppler and color flow mapping may be necessary when they add significant information to the patient’s condition or treatment plan.
When Should CPT Code 93306 be Used?
CPT 93306 fits when the clinical order and completed report support a full transthoracic echocardiogram with Doppler and color flow. Common clinical reasons may include evaluation of suspected valve disease, murmur, cardiomyopathy, ventricular function, structural heart disease, dyspnea, heart failure symptoms, or other cardiac concerns where a full study is clinically supported.
The diagnosis code should match the reason for the test. CMS billing guidance states that claims submitted without a valid ICD-10-CM diagnosis code can be returned as incomplete. For services that require a referring or ordering physician, the claim must also report that physician’s name and NPI.
For example, 93306 may be appropriate for a new murmur workup or a suspected heart failure case when the report documents chamber function, valves, Doppler findings, and interpretation.
When 93306 May Be The Wrong Code?
CPT 93306 should not be selected just because an ultrasound machine was used or because the word “echo” appears in the chart. The report must match the service. If the provider performed only a limited follow-up study, a limited TTE code may be more appropriate. If Doppler and color flow were not performed or not documented, 93306 may not be supported.
AAPC’s coding comparison explains that 93306 describes a complete transthoracic echo with Doppler and color flow, while 93308 is used for a limited or follow-up transthoracic echo that evaluates fewer structures than a complete study.
Documentation Requirements for CPT 93306
The strongest defense for CPT 93306 is a complete report that makes the code choice obvious. The chart should support the order, the medical need, the image acquisition, the Doppler work, and the interpretation.
A clean report should usually include the patient’s clinical indication, date of service, ordering or referring provider when required, image documentation, cardiac structures evaluated, measurements, Doppler findings, color flow findings, limitations if any structures were not visualized, physician interpretation, and signature.
The Final Report Should Show The Full Study
The final report should not read like a short note. It should show that the exam was complete. If the aorta, pericardium, or a valve could not be assessed, the limitation should be stated rather than hidden. Missing structure documentation can make a complete code harder to defend during review.
ICD-10 Support Should Match The Reason For The Test
ICD-10 coding should not be chosen after the claim is denied. The diagnosis should connect to the documented reason for the TTE. For example, a study ordered for dyspnea should not be billed with a valve diagnosis unless the chart supports it. CMS billing articles for TTE include ICD-10-CM diagnosis guidance and remind providers that valid diagnosis coding is required for claim processing.
Modifiers Used With CPT Code 93306
The same CPT code can be billed in different ways depending on who performed the technical part and who interpreted the study. This is where modifier use matters.
Modifier 26
Modifier 26 is used when the provider bills only the professional component. In a common hospital-based example, the hospital owns the equipment and staff perform the scan, while a cardiologist interprets the images and signs the report. The cardiologist or group may bill 93306 with modifier 26 for the interpretation portion, depending on payer rules.
Modifier TC
Modifier TC is used when billing only the technical component. This covers the equipment, technician work, facility resources, and related technical costs. If an imaging center performs the test but another physician group interprets it, the imaging center may bill the technical portion while the interpreting provider bills the professional portion, subject to payer policy.
Global Billing
If the same practice provides the equipment, staff, image acquisition, physician interpretation, and report, the claim may be submitted globally without modifier 26 or TC. Billing teams should still check payer contracts, place-of-service rules, and whether the provider is allowed to bill globally in that setting.
CPT 93306 Vs 93307 Vs 93308
The most common coding mistake is choosing 93306 when the report supports a different echocardiography code. The difference depends on completeness and Doppler documentation.
CPT 93306 is used for a complete TTE with spectral Doppler and color flow Doppler. CPT 93307 is used for a complete TTE without those Doppler components. The CPT 93308 is used for a limited or follow-up TTE. AAPC’s comparison notes that 93308 evaluates fewer structures than the complete study described by 93306.
Use 93307 when the study is complete, but the required Doppler and color flow elements for 93306 are not performed or documented. Use 93308 when the study is limited, such as a focused follow-up for pericardial effusion, ventricular function, or another narrow question. The report should make that distinction clear.
Reimbursement Considerations for CPT 93306
Payment for CPT 93306 depends on payer, setting, geography, contract terms, modifier use, and whether the claim is billed as global, professional only, or technical only. Medicare payment is tied to the Medicare Physician Fee Schedule, which CMS updates through annual rulemaking and fee schedule files.
The American Society of Echocardiography’s CY 2026 Medicare Physician Fee Schedule comparison lists national payment figures for 93306 and separates the global service, technical component, and professional component. Those values are helpful for directional review, but actual payment can differ based on locality, site of service, payer policy, and contract terms.
Billing teams should avoid treating online reimbursement figures as fixed rates. A payer may reduce, deny, bundle, or request records when the claim does not match coverage rules.
Common Denial Reasons for CPT 93306
Denials for 93306 usually stem from weak documentation, not the code itself. Common issues include unclear medical necessity, unsupported ICD-10 codes, incomplete exam details, missing Doppler or color flow findings, wrong modifiers, repeat studies without a documented reason, or duplicate billing when global, TC, and 26 components are not separated correctly during claim review or audits.
Pre-Billing Checklist for CPT 93306
Before submitting a CPT 93306 claim, the billing team should verify the order, the clinical indication, the final signed report, the structures evaluated, the Doppler documentation, color flow documentation, the ICD-10 support, the place of service, the modifier use, and the payer-specific policy. For Medicare, TTE billing articles and LCDs should be reviewed by the jurisdiction because local coverage rules can affect diagnosis support and documentation expectations.
The simplest audit question is this: Does the report prove a complete TTE with Doppler and color flow, or does it only imply one? If the report only implies it, coding 93306 becomes harder to defend.
Tired of dealing with rejected echocardiography claims?
Get a complimentary billing assessment and find out how our cardiology coding experts can help minimize your denials.
Clean Billing Starts With The Report
CPT code 93306 is correct only when the clinical record supports a complete transthoracic echocardiogram with Doppler and color flow. A claim built on a thin report is easy to question, even when the test was performed correctly. The best protection is simple: document the indication, complete structures, Doppler and color flow findings, limitations, interpretation, modifier choice, and diagnosis support before the claim leaves the billing queue.
FAQs
Does CPT 93306 include Doppler?
Yes. CPT 93306 includes spectral Doppler and color flow Doppler as part of a complete transthoracic echocardiogram. CMS states that 93306 should be used when Doppler is combined with a complete echocardiogram for dates of service on or after January 1, 2009.
Can CPT 93306 be billed with separate Doppler codes?
In routine billing, separate Doppler codes should not be added when billing 93306 because Doppler and color flow are already part of the service. CMS also directs billers to check NCCI and OPPS edits before billing Medicare claims.
What modifier is used for CPT 93306?
Modifier 26 is used for the professional component only. Modifier TC is used for the technical component only. No component modifier is typically used when the same entity bills the full global service.
What is the difference between 93306 and 93308?
CPT 93306 is for a complete TTE with Doppler and color flow. CPT 93308 is for a limited or follow-up TTE that evaluates fewer structures. The final report should support the level of service selected.
