Key Takeaways
- CPT 93306 = complete transthoracic echocardiogram (TTE) with 2D, M-mode (when performed), spectral Doppler, and color flow Doppler in one combined study.
- All three elements—complete 2D study, spectral Doppler, and color Doppler—must be documented or you should bill 93307 or 93308 instead.
- Use professional/technical split with modifier 26 (professional) or TC (technical) based on the setting and who owns the equipment.
- Accurate documentation of medical necessity (ICD-10 diagnosis) is the leading factor in avoiding 93306 denials.
What is CPT code 93306?
CPT code 93306 describes a complete transthoracic echocardiogram (TTE) for the evaluation of cardiac structure and function, including 2D imaging, M-mode recording when performed, spectral Doppler echocardiography, and color flow Doppler echocardiography. In plain terms, 93306 is the “all-in-one” complete echo: it bundles the full ultrasound study of the heart with both types of Doppler in a single code.
Because 93306 is a bundled, complete study, you cannot separately report the Doppler components (such as 93320 or 93325) in addition to it—they are already included. If a complete study with both Doppler types was not performed, a different code applies.
What 93306 must include
To support 93306, the report must document each required component. Use the reference table below as a documentation checklist.
| Component | Required for 93306? | Notes |
|---|---|---|
| Complete 2D imaging | Yes | Full structural assessment of chambers, valves, and great vessels |
| M-mode | When performed | Not mandatory, but documented if done |
| Spectral Doppler | Yes | Pulsed and/or continuous-wave Doppler |
| Color flow Doppler | Yes | Color flow velocity mapping |
| Interpretation & report | Yes | Signed report supporting medical necessity |
93306 vs. related echocardiography codes
Choosing the right echo code depends on whether the study was complete and which Doppler components were performed. This comparison table clarifies the most common TTE codes.
| CPT code | Study type | Doppler included? |
|---|---|---|
| 93306 | Complete TTE | Spectral + color flow Doppler (both) |
| 93307 | Complete TTE | No Doppler |
| 93308 | Limited or follow-up TTE | Follow-up / limited study |
| 93320 | Doppler echo (spectral) | Add-on; not billed with 93306 |
| 93325 | Doppler color flow | Add-on; not billed with 93306 |
Professional vs. technical components (modifiers 26 and TC)
Echocardiography has two billable parts, and the modifier you use depends on the setting:
- Modifier 26 (professional component) — the physician's interpretation and written report. Use when the provider reads a study performed on equipment they do not own (e.g., a hospital).
- Modifier TC (technical component) — the equipment, sonographer, and supplies. Use when the facility owns the equipment but does not interpret.
- Global (no modifier) — report 93306 with no modifier when the same entity performs and interprets the study (typical in a physician office that owns the machine).
How to bill CPT 93306 cleanly
Follow this workflow to keep 93306 claims clean and audit-ready:
- Confirm medical necessity — link an appropriate ICD-10 diagnosis (e.g., heart failure, murmur, valvular disease) that supports the echo.
- Verify the complete study — ensure 2D + spectral Doppler + color Doppler are all documented; otherwise choose 93307/93308.
- Select the correct modifier — 26, TC, or global based on equipment ownership and interpretation.
- Do not unbundle Doppler — never add 93320 or 93325 to 93306.
- Check payer & frequency rules — some payers limit echo frequency or require prior authorization.
- Scrub for NCCI edits before submission, then submit electronically.
For broader coding context, see our complete guide to CPT, the orthopedic CPT guide, and our 2026 telehealth CPT guide for related procedural coding.
Common 93306 denials and how to prevent them
- Missing Doppler documentation — if both Doppler types aren't recorded, 93306 is downcoded; document thoroughly.
- Unbundling — reporting 93320/93325 alongside 93306 triggers edits.
- Wrong modifier — 26 vs. TC vs. global mismatched to the setting.
- Insufficient medical necessity — the ICD-10 diagnosis must justify the study.
- Frequency limits — repeat echoes without supporting documentation are denied.
Frequently asked questions
CPT code 93306 is used to report a complete transthoracic echocardiogram (TTE) that includes 2D imaging, M-mode when performed, spectral Doppler, and color flow Doppler in a single study. It evaluates cardiac structure and function and is one of the most common cardiology procedure codes.
Both 93306 and 93307 are complete transthoracic echocardiograms, but 93306 includes spectral and color flow Doppler, while 93307 is a complete TTE performed without Doppler. If the study includes Doppler, bill 93306; if no Doppler was performed, bill 93307.
No. CPT 93306 already bundles spectral Doppler and color flow Doppler into the complete study, so the add-on Doppler codes 93320 and 93325 should not be reported separately with 93306. Doing so triggers NCCI edits and denials.
Use modifier 26 (professional component) with 93306 when the physician only interprets the echocardiogram and writes the report but does not own the equipment—common when a study is performed at a hospital and read by a physician. Use modifier TC for the technical component, or no modifier (global) when one entity both performs and interprets the study.
To bill 93306, the report must document a complete 2D study, spectral Doppler, and color flow Doppler, along with M-mode if performed, plus a signed interpretation and a supporting ICD-10 diagnosis establishing medical necessity. If any required Doppler element is missing, a different echo code applies.
Yes, Medicare reimburses CPT 93306 when it is medically necessary and properly documented. Reimbursement varies by setting and whether the global, professional (modifier 26), or technical (modifier TC) component is billed, and some payers apply frequency limits or prior-authorization requirements.