CPT Code 93306: Transthoracic Echocardiography With Doppler

CPT code 93306 reports a complete transthoracic echocardiogram (TTE) with real-time 2D imaging, M-mode when performed, spectral Doppler, and color-flow Doppler. 

It belongs to the diagnostic cardiovascular imaging category — not E/M — and carries no MDM requirement or time threshold. Code selection depends entirely on whether a complete study was performed and whether both Doppler components are included.

The most consequential compliance issue with 93306 is not clinical complexity — it is unbundling. Spectral Doppler (93320) and color-flow Doppler (93325) are already included in 93306. 

The Medicare Appeals Council has upheld denials of separately reported Doppler add-ons billed with the same study, even when modifier 59 was used. 

First Coast’s August 2026 targeted review of 93306 identified medical necessity and insufficient documentation as the leading denial reasons.

What does CPT code 93306 cover?

The essential reference facts for 93306 billing.

Detail	CPT 93306
Description	Complete TTE with 2D, M-mode, spectral Doppler, and color-flow Doppler
Category	Diagnostic Cardiovascular Imaging
Patient type	N/A (diagnostic procedure)
MDM level	N/A (not an E/M code)
Time	No time threshold
Common modifiers	26 (professional), TC (technical), 76/77 (repeat)
Medicare rate	~$196.73 global / ~$67.47 professional (2026)
Commonly compared with	CPT 93308

A complete TTE for 93306 must contain specific measurements — LV end-diastolic and end-systolic diameter, wall thickness, left-atrial diameter, aortic-valve excursion, and a qualitative description of LV function (or valid substitutes). 

Doppler documentation should identify the modes used and provide both qualitative and quantitative findings.

When should you use CPT 93306?

93306 is the correct code when a genuinely complete TTE study includes both spectral and color-flow Doppler.

Use CPT 93306 when

• The study is a complete transthoracic echocardiogram (not limited or follow-up)
• Both spectral Doppler and color-flow Doppler are performed and documented
• The required complete-study measurements are obtained
• Medical necessity supports the examination

When not to use it

• The study is limited or follow-up — use 93308
• A complete TTE was performed but without Doppler components — use 93307
• The clinical situation calls for a congenital/pediatric TTE — congenital codes 93303/93304 may apply
• The echo serves as integral guidance during a transcatheter valve procedure — NCCI bundling restrictions apply

How is CPT 93306 selected?

93306 has no MDM pathway and no time threshold. Selection depends on the scope and components of the echocardiographic study performed.

Required components

The study must be complete (not limited or follow-up) and must include all of these elements documented in the report

• Color-flow Doppler
• M-mode recording when performed
• Real-time 2D imaging with image documentation
• Spectral Doppler with qualitative and quantitative findings
• Complete evaluation of cardiac chambers, valves, and function
• Required measurements — LV end-diastolic and end-systolic diameter, LV wall thickness, left-atrial diameter, aortic-valve excursion, and qualitative LV function (or valid substitutes such as LV volumes, ejection fraction, and mass)

If any of these are missing from the documentation, the study may not support 93306. 

A report that omits Doppler findings — even when the sonographer performed them — creates audit vulnerability because the billed code includes those components.

Component billing

93306 has a PC/TC split. Bill global when the same entity provides both acquisition and interpretation. Use 93306-26 for interpretation only and 93306-TC for acquisition only. The national 2026 professional component baseline is ~$67.47 while the technical component is ~$129.26.

What documentation supports CPT 93306?

For 93306, the documentation burden centers on proving a complete study was actually performed — with all required measurements and Doppler findings.

The report should include:

• Color-flow Doppler findings
• Formal written interpretation
• Retained images available for review
• Ordering/referring physician name and NPI when applicable
• Spectral Doppler modes and qualitative/quantitative findings
• For repeat studies, the clinical reason a new examination is needed
• Medical necessity with relevant history, symptoms, and clinical indication
• Complete study measurements (LV dimensions, wall thickness, LA diameter, aortic-valve excursion, LV function)

CMS has an approved RAC Topic 0111 specifically authorizing review of TTE medical necessity and documentation. Current 2026 MAC reviews confirm that weak medical-necessity documentation and missing measurement data remain the primary denial triggers.

How much does CPT 93306 reimburse?

Payment depends on the billing component (global, professional, or technical), setting, and geography.

Payment type	2026 rate
Medicare global (national baseline)	~$196.73
Medicare professional (93306-26)	~$67.47
Medicare technical (93306-TC)	~$129.26
Hospital OPPS (facility payment)	~$558 (separate institutional payment)
Medicaid	Varies by state

Medicare rates from CMS 2026 PFS national baselines (5.89 total RVU × ~$33.40 conversion factor). Geographic adjustment ranges roughly $175-$266 by locality.

In hospital outpatient settings, the physician bills the professional component (93306-26 at ~$67.47) while the facility receives its own institutional payment under OPPS — roughly $558 per the July 2026 OPPS Addendum B. Do not confuse the physician PFS rate with the total facility reimbursement.

Which modifiers apply to CPT 93306?

93306 has a unique modifier profile because of its PC/TC structure and Doppler bundling rules.

Modifier	When it applies
26	Professional component only — interpretation and report
TC	Technical component only — acquisition and equipment
76	Repeat procedure by the same physician when medically necessary
77	Repeat procedure by a different physician
59/XE/XS	Only when a current NCCI indicator-1 edit exists for a genuinely distinct service — NOT for unbundling Doppler

Modifier 25 belongs on a same-day E/M code, not on 93306 itself. A same-day cardiology office visit and echo can coexist — but modifier 25 goes on the E/M and only when the evaluation is significant and separately identifiable from the procedure.

Critically — modifier 59 cannot unbundle 93320 or 93325 from the same 93306 study. The Medicare Appeals Council has specifically upheld denials in this scenario.

93306 is not a Medicare telehealth service. A cardiologist remotely reading echo images is performing a professional diagnostic interpretation — not furnishing a telehealth encounter. Do not use modifiers 95 or 93.

CPT 93306 vs. 93308 — which one fits?

The 93306/93308 distinction turns on the scope of the study — complete versus limited.

Feature	CPT 93306	CPT 93308
Study scope	Complete TTE	Limited/follow-up TTE
Doppler	Spectral + color included	Not necessarily included
Typical use	Full cardiac evaluation — chambers, function, valves, flow	Targeted reevaluation — known effusion, focused LV-function check
Medicare rate (2026)	~$196.73	~$101.20
Work RVU	1.42	0.52

Choose 93306 when the documentation demonstrates a genuinely complete TTE with both spectral and color-flow Doppler.

Choose 93308 when the provider performs a focused or limited examination rather than assessing the full complete-study scope. 

A repeat study can still be 93306 if a complete study is medically necessary and actually performed — “repeat” alone does not dictate 93308.

What billing errors should you avoid with CPT 93306?

Five errors drive the majority of 93306 denials and audit exposure.

1. Separately billing 93320 or 93325 with the same study 

Spectral and color Doppler are bundled into 93306. The Medicare Appeals Council has upheld denials even when modifier 59 was used to unbundle them. Never bill Doppler add-ons for the same TTE.

2. Reporting 93306 for a limited examination 

If the report does not demonstrate complete-study scope and measurements, the code is overstated. Compare the documented structures against the required measurements before submitting.

3. Missing Doppler documentation in the report 

93306 explicitly includes spectral and color-flow Doppler. A report that never documents those findings fails to prove the billed service was performed. State the Doppler modes used and provide both qualitative and quantitative findings.

4. Incorrect global/26/TC billing 

Billing global when the practice supplied only the interpretation — or billing 26 when the entity provided the complete service — can duplicate payment between physician and facility. Map who owns the equipment and who performs the interpretation before assigning components.

5. Repeating 93306 without documenting clinical necessity 

Medicare specifically reviews repeat TTE frequency. Repeated testing should reflect clinical change or suspected disease progression. State what changed, why new imaging is needed, and which prior study was reviewed.

Frequently asked questions about CPT 93306

Here are some commonly asked questions about CPT 93306: