Cardiology CPT Codes
Cardiology CPT codes live mostly in the Medicine section, with interventional procedures over in Surgery. Day to day, cardiology billing revolves around a familiar set: echocardiography, ECGs, Holter monitoring, and stress testing. These are high-RVU diagnostic codes, and payers watch them closely. Expect medical-necessity checks on nearly every claim.
Reviewed by the ClinicsFlows editorial team · How we source this
Cardiology CPT codes
Echocardiography, Complete with Doppler
Complete transthoracic echo including 2D, spectral Doppler, and color flow Doppler. Highest-RVU routine cardiology diagnostic code.
Echocardiography, Complete 2D Only
Complete 2D echo without Doppler components. Use when Doppler is not performed.
Echocardiography, Follow-up or Limited
Limited or follow-up echo for re-evaluating a specific finding. Lower RVU than complete study.
Stress Echocardiography
Echo performed during or immediately after cardiovascular stress, evaluates wall motion abnormalities.
Electrocardiogram (ECG), Routine
12-lead ECG with interpretation and report included. Global code.
ECG, Tracing Only
Technical component only, tracing without interpretation. Use -TC modifier or this code when splitting components.
ECG, Interpretation and Report Only
Professional component, interpretation without tracing. Use when reading strips from another facility.
Cardiovascular Stress Test
Stress testing with supervision, interpretation, and report. Includes physician supervision of exercise test.
Stress Test, Tracing Only
Technical component of stress test without interpretation.
Codes in blue have full detail pages with documentation requirements, billing mistakes, and FAQ.
Cardiology billing notes
93306 (complete echo with Doppler) is one of the highest-paying routine diagnostic codes in medicine, which is exactly why auditors love it. Documentation and the supporting diagnosis need to be airtight.
Most cardiology diagnostics split into a technical component and a professional component. When the facility and the interpreting physician bill separately, the facility appends TC and the physician appends 26.
Stress testing comes in pieces: supervision (93015), tracing only (93017), and interpretation (93018). Different providers can bill different pieces, but nobody bills the global and a piece.
Bundling rules bite hard here. 93306 already includes Doppler, so billing 93320 on top of it is a guaranteed denial and an unbundling flag.
Frequently asked questions about cardiology billing
What is the most common cardiology CPT code?▼
93000, the routine 12-lead ECG with interpretation, is billed more often than any other cardiology code because nearly every cardiac workup starts with one. Among imaging codes, 93306 (complete echo with Doppler) leads by a wide margin.
What's the difference between 93306, 93307, and 93308?▼
All three are transthoracic echos. 93306 is the complete study with spectral and color Doppler, 93307 is a complete study without Doppler, and 93308 is a limited or follow-up study that re-checks a specific finding. If Doppler was performed as part of a complete study, 93306 is the right code, and billing Doppler separately on top of it is unbundling.
When do I use modifiers TC and 26 on cardiology codes?▼
When the equipment owner and the interpreting physician aren't the same biller. The facility that owns the machine and employs the tech bills with TC; the cardiologist who reads the study bills with 26. One party billing globally covers both, and then neither modifier applies.
Why do cardiology claims get denied for medical necessity so often?▼
Because the diagnostic codes pay well and payers pair each one against the diagnosis on the claim. An echo billed with a vague or unrelated ICD-10 code bounces even when the study was clinically justified. Check the payer's coverage policy for supported diagnoses before the claim goes out, not after the denial.
Sources
- Code set structure and updates: American Medical Association — CPT
- Fee schedule and component billing rules: CMS Medicare Physician Fee Schedule
- How we research and verify: our editorial policy
CPT® is a registered trademark of the American Medical Association. Content on this page is original educational writing, not a reproduction of AMA-copyrighted descriptions. Verify codes and payer rules before billing.