Echocardiography is one of the most important diagnostic tools in cardiology, providing real-time structural and functional assessment of the heart. CPT 93306 is one of the most frequently used—and frequently misunderstood—codes in cardiovascular billing. Because it includes both spectral and color Doppler, many practices struggle to determine when 93306 is appropriate, how to document it, and how to avoid denials from Medicare and commercial payers.
This guide offers a comprehensive, practical explanation of when to use CPT 93306, documentation requirements, payer-specific rules, and common mistakes that lead to denials. It is designed for cardiologists, internists, family physicians, and billing teams working with cardiovascular services.
Improve reimbursements instantly by using our detailed CPT 93000–93010 EKG Billing Guide to code EKG services correctly the first time.
What Is CPT Code 93306?
CPT 93306 is defined as:
“Echocardiography, transthoracic, real-time with image documentation (2D), includes M-mode recording when performed, complete, with spectral Doppler and color flow Doppler echocardiography.”
In simple terms, 93306 = comprehensive transthoracic echo (TTE) + spectral Doppler + color Doppler.
It represents the complete study and includes:
- 2D echo (anatomical visualization)
- M-Mode (motion/time measurements)
- Spectral Doppler (flow velocity & direction)
- Color Doppler (blood flow mapping)
All components must be performed to use 93306.
93306 vs. 93307 vs. 93308 (Key Differences)
Many clinicians confuse these three codes. Here’s the breakdown:
| Code | Description | Includes Doppler? | Study Type |
| 93306 | Complete TTE with spectral + color Doppler | Yes | Complete |
| 93307 | Complete TTE without Doppler | No | Complete (no Doppler) |
| 93308 | Limited/Follow-up TTE | Only if added with 93321/93325 | Limited |
If both spectral Doppler AND color Doppler are performed → must bill 93306.
If no Doppler is performed → use 93307.
If the exam is limited (e.g., follow-up pericardial effusion) → 93308.
Ensure clean claims for non-Doppler echo studies using our CPT 93307 Transthoracic Echocardiogram Billing Guide fully updated for 2024–2025.
When Should CPT 93306 Be Used?
Use 93306 when:
✓ The exam is complete
All cardiac chambers, valves, pericardium, and great vessels must be evaluated.
✓ Both Doppler components are performed
- Spectral Doppler (PW and CW)
- Color flow Doppler
✓ There is a medical necessity
Payers require a documented reason, such as:
- R06.02 (Shortness of breath)
- R07.9 (Chest pain)
- I50.9 (Heart failure)
- R00.2 (Palpitations)
- I10 (Hypertension)
- I48.91 (Atrial fibrillation)
- I34–I38 (Valve disorders)
✓ A formal interpretation is completed
The provider MUST generate and sign a full report.
Do NOT use 93306 for:
- Screening without symptoms
- Research studies
- Administrative evaluations
- “Routine” echoes without medical necessity
- Limited studies
Documentation Requirements for 93306
Documentation must support both the complete study AND Doppler use. Reduce audit risk by reviewing our practical CPT 93308 Limited Echocardiogram Billing Guide designed for real-world cardiology documentation needs.
Your report must include:
1. Cardiac Structures Examined (Complete Study)
- LV size, volume, systolic function (LVEF)
- RV size and function
- LA & RA size
- Aortic root & ascending aorta
- IVC and collapsibility
- Pericardial effusion evaluation
- Valve structure & morphology
2. Spectral Doppler Measurements
Must document flow velocities in at least:
- Mitral inflow
- Aortic outflow
- Tricuspid regurgitation jet
- Pulmonic flow is indicated
3. Color Doppler Findings
Examples:
- Mitral regurgitation
- Aortic insufficiency
- Tricuspid regurgitation
- Shunts if present
4. Left Ventricular Ejection Fraction (LVEF)
Required by nearly all payers.
5. Interpretation & Impression
Clear final impression including:
- Primary clinical concern
- Abnormal findings
- Severity of dysfunction
- Comparison to prior studies
- Management suggestions when appropriate.
6. Provider Signature & Credentials
Medicare will deny or recoup claims if the signature is missing. Get complete clarity on supervision and split-billing requirements from our CPT 93016 Stress Test Supervision Billing Guide optimized for cardiology practices.
Payer-Specific Billing Rules for CPT 93306
Medicare
Medicare covers 93306 when:
- The test is medically necessary
- A complete report is generated
- Doppler findings are documented
Medicare frequently denies 93306 if:
- The Doppler component isn’t documented
- The exam is limited but billed as complete
- The study is duplicated or repeated within a short interval
Medicaid
Medicaid rules vary by state, but common denials occur when:
- The echo is billed as “screening.”
- There is insufficient medical necessity
- Limited studies are billed using 93306
- Documentation lacks Doppler elements
Commercial Payers
Most commercial insurers follow Medicare rules.
Some carriers bundle 93306 if performed with certain office visits unless modifier -25 is attached to the E/M code. Avoid stress-test denials and understand payer variations with our
CPT 93015 Cardiac Stress Test Billing Guide covering supervision, NCCI edits, and interpretation rules.
When to Use Modifier 26 and TC
In a cardiology group or hospital setting, the technical and professional components are often billed separately.
- 93306-26 → Professional component only (interpretation)
- 93306-TC → Technical component only (equipment + tech)
- 93306 (no modifier) → Global billing
Examples:
- Cardiologist interprets the hospital echo → 93306-26
- Hospital bills technical portion → 93306-TC
- Private practice performs & interprets → 93306 global
Common Denials for CPT 93306 (and How to Avoid Them)
❌ 1. Missing Doppler documentation
If the report does NOT explicitly mention spectral Doppler & color Doppler → payers downcode to 93307 or deny.
❌ 2. No medical necessity
“Routine echo” = denial.
❌ 3. Modifier errors
Incorrect use of global billing vs 26/TC.
❌ 4. Incomplete final impression
Payers require formal interpretation, not just measurements.
❌ 5. Duplicate testing
Back-to-back echoes without justification will trigger audits.
❌ 6. Using 93306 for limited exams
Follow-up studies should use 93308.
Correct & Incorrect Billing Examples
Correct Example
A patient presents with dyspnea, edema, and suspected heart failure.
A complete echo and full Doppler evaluation are performed.
→ Bill 93306
Incorrect Example
Provider performs a quick reassessment of pericardial effusion.
Only limited structures are evaluated.
→ Should bill 93308, NOT 93306.
Correct Example with Split Billing
The hospital performs an echo (technical).
The cardiologist interprets.
→ Hospital bills 93306-TC
→ Cardiologist bills 93306-26
Final Thoughts
CPT 93306 is one of the most commonly billed cardiology procedures, but also one of the most commonly denied when documentation does not support a complete exam with both Doppler components. Understanding the requirements and payer policies helps ensure accurate reimbursement and compliance.
If your cardiology or internal medicine practice struggles with echo denials or coding challenges, Global Tech Billing LLC helps clinics optimize documentation workflows, review payer rules, and reduce repeat denials for cardiovascular imaging.
FAQ: Common Questions About CPT 93306
1. Can NPs or PAs bill 93306?
Yes—if they perform and interpret the study in compliance with the state scope of practice.
2. Can 93306 be billed with an office visit?
Yes, if medically necessary. Some payers require modifier 25 on the E/M code.
3. Is color Doppler required for 93306?
Absolutely. Both spectral AND color Doppler must be documented.
4. Can I bill 93306 and 93307 together?
No—93306 already includes the full study.
5. Can 93306 be done via telehealth?
No—the test itself is in-person. Interpretation (modifier 26) may be remote.
6. How often can a patient get an echo?
Medicare allows it based on medical necessity. Repeated studies need a clear justification.
7. Does 93306 include contrast?
No. Use Q9950–Q9957 for contrast agents as appropriate.
