Complete Guide to the Most Common Cardiology CPT & ICD-10 Codes
- Sirius solutions global
- 6 hours ago
- 8 min read
If you work in cardiology billing, you know this is not like coding for primary care. The stakes are higher, the procedures are more complex, and payer scrutiny is relentless. One wrong code on a cardiac catheterization claim could mean a denial worth thousands of dollars. Get your diagnosis coding wrong and the entire procedure gets flagged as not medically necessary.
We have seen practices lose serious money because they were using outdated codes or pairing CPT and ICD-10 codes incorrectly. In 2026, with new coding updates and increased oversight, the margin for error has gotten even smaller.
This guide walks you through the most common cardiology CPT and ICD-10 codes you need to know. Not just a list, but real context about when to use them, how to pair them correctly, and what mistakes to avoid.
Understanding CPT and ICD-10 Codes in Cardiology
CPT codes are Current Procedural Terminology codes. These describe what you did during the patient encounter. Performed an echocardiogram? That is a CPT code. Placed a stent? Different CPT code. These determine reimbursement.
ICD-10 codes are diagnosis codes. These explain why you did what you did. They justify medical necessity. Without the right diagnosis code, even a perfectly coded procedure gets denied by payers.
The critical part is that CPT and ICD-10 codes have to make sense together clinically. You cannot bill for a complex cardiac catheterization with only "chest pain unspecified" as your diagnosis. Payers will reject that immediately.
How CPT and ICD-10 Codes Work Together
Every cardiology claim tells a story. The ICD-10 code sets up the problem. The patient has atrial fibrillation. The CPT code describes what you did. You performed an ablation. If these do not match logically, the claim gets denied.
Medical necessity is everything in billing. Just because a cardiologist performed a procedure does not mean it automatically gets paid. The diagnosis has to support why that procedure was appropriate for that specific patient.
Major Cardiology Coding Changes in 2026
Remote cardiac monitoring codes have gotten more specific based on device type and transmission frequency.
Cardiac imaging with AI assistance is getting separate coding considerations from some payers.
Heart failure coding requires much more specificity now. You need to specify systolic, diastolic, acute, chronic, right-sided, or left-sided.
Structural heart procedures like TAVR face intense payer scrutiny and increased documentation requirements.
The bottom line is that 2026 is not the year to coast on old knowledge.
Most Common Cardiology CPT Codes You Need to Know
Let us break down the CPT codes by category so you can actually find what you need when you need it.
Office Visit Codes
New patient office visits are 99202 through 99205. Established patient visits are 99211 through 99215. The level depends on medical decision making complexity and time spent.
Do not undercode. If your cardiologist spent 45 minutes managing a complex heart failure patient, that is probably a level 5 visit. Make sure your documentation supports it.
Do not forget prolonged service codes available. Code 99417 can be added when visits go significantly over typical time.
ECG and EKG Codes
Electrocardiograms are performed constantly in cardiology, so you need to know these codes.
93000 - Complete ECG with full interpretation and report (most common)
93005 - Tracing only, no interpretation
93010 - Interpretation and full report only
The split between these codes matters when one provider performs the test and another interprets it. Make sure you code for what your provider did in that encounter.
Stress Testing Codes
93015 is your standard exercise stress test with ECG monitoring and full supervision. Codes 93016, 93017, and 93018 are component codes for billing pieces separately.
If you add nuclear imaging, you need codes from the 78000 series. Code 78452 is a myocardial perfusion imaging procedure.
Understand when to use modifier 26 for a professional component versus billing the complete code number.
Echocardiography Codes
Echos are high revenue generators and get audited frequently.
93306 - Complete transthoracic echocardiogram (most common)
93307 - Limited or follow-up echo
93312 - Transesophageal echo (more invasive, higher reimbursement)
93351 - Stress echocardiogram
93356 - Myocardial strain imaging
Documentation must clearly show what structures were evaluated and the clinical indication.
Cardiac Catheterization and Angiography
93458 - Diagnostic coronary angiography
93460 - Combined left and right heart catheterization
93571 - Fractional flow reserve measurement
Catheterization coding is complex. Different codes apply depending on vessels accessed and interventions performed. Documentation must be extremely detailed.
PCI, Stents, and Interventions
92928 - Coronary stent placement
92920 - Balloon angioplasty without stenting
92933 - Atherectomy combined with stenting
These procedures often involve multiple codes. You must know NCCI edits to avoid bundling denials.
Electrophysiology and Ablation
93656 - Catheter ablation for atrial fibrillation
93653 - Ablation for supraventricular tachycardia
93620 - Comprehensive electrophysiology study
Documentation requirements are intense. Specify the arrhythmia treated, approach used, and outcome.
Pacemakers, ICDs, and Cardiac Devices
33206-33208 - Pacemaker insertion (single, dual, or biventricular chamber)
33249 - Implantable cardioverter defibrillator insertion
93288 - Device interrogation in office
93296 - Remote device monitoring
Use the right code based on device type and whether it is initial implant, replacement, or generator change.
Advanced Imaging
75574 - Coronary CT angiography
78452 - Nuclear myocardial perfusion imaging
75561 - Cardiac MRI
In many cases, you will need prior authorization for these codes.
So before moving forward with the test, make sure the insurance approval is already in place.
Structural Heart Procedures
33361-33366 - TAVR (transcatheter aortic valve replacement)
93580 - ASD or PFO closure
33990 - Intra-aortic balloon pump insertion
These expensive procedures face intense scrutiny. Every detail must be documented perfectly.
Most Common Cardiology ICD-10 Diagnosis Codes
Hypertension
I10 - Essential hypertension (most common cardiology diagnosis)
I11.9 - Hypertensive heart disease without heart failure
Coronary Artery Disease
I25.10 - Atherosclerotic heart disease without angina
I20.0 - Unstable angina
I25.110 - CAD with unstable angina
Heart Failure
I50.22 - Chronic systolic heart failure
I50.32 - Chronic diastolic heart failure
I50.812 - Right-sided heart failure
Specify acute versus chronic and compensated versus decompensated for accurate coding.
Arrhythmias
I48.0 - Paroxysmal atrial fibrillation
I48.19 - Persistent atrial fibrillation
I49.5 - Sick sinus syndrome
Valve Disorders
I34.0 - Mitral regurgitation
I35.0 - Aortic stenosis
I36.1 - Tricuspid insufficiency
Other Common Diagnoses
I42.9 - Cardiomyopathy
I27.20 - Pulmonary hypertension
R07.9 - Chest pain
R06.02 - Shortness of breath
R00.2 - Palpitations
CPT and ICD-10 Pairing Examples
Let us give you some real-world examples of how these codes work together.
Notice how each procedure has a diagnosis that makes clinical sense. That is what you are aiming for in every claim.
Critical Modifiers for Cardiology Billing
Modifiers can make or break your claims. Here are the ones you need to master:
Modifier 25 is used when you perform an E/M visit and a procedure on the same day. The visit has to be significant and separately identifiable from the procedure. This gets audited constantly, so your documentation better support it clearly. You need to show why the visit was necessary beyond just deciding to do the procedure.
Modifier 26 indicates you are billing for the professional component only, just the interpretation. Modifier TC is the technical component, covering the equipment and technician. If your practice does not own the imaging equipment, you only bill modifier 26. If you own everything and employ the techs, you bill the complete code without modifiers.
Modifier 59 indicates distinct procedural services when you are doing multiple procedures that might otherwise be bundled together. Use this carefully because payers scrutinize it heavily.
LD, LC, and RC are artery-specific modifiers used in catheterization and PCI procedures. LD is for the left anterior descending artery, LC is for the left circumflex, and RC is for the right coronary artery. These tell the payer exactly which vessel you treated.
Modifiers 76 and 77 indicate repeat procedures. Use 76 when the same physician repeats a procedure on the same day. Use 77 when a different physician does it.
Using modifiers incorrectly is a fast track to denials and audits. When in doubt, check the modifier definitions and payer-specific guidelines.
Top Denial Risks in Cardiology Billing
Now it’s time to tell you what gets claims denied most often so you can avoid these traps.
Unspecified diagnosis codes are a huge problem. If you are still using codes that end in 9 for unspecified conditions, you are asking for trouble. Payers want specificity. Instead of I25.9 for "chronic ischemic heart disease unspecified," use I25.10 for "atherosclerotic heart disease of native coronary artery without angina" if that is more accurate.
Incorrect modifier usage causes endless problems. Using modifier 25 when the visit was not truly separate from the procedure will get you denied. Forgetting to use modifier 26 when you only did the interpretation will result in overpayment and eventual recoupment.
Missing prior authorization is a killer, especially for high-cost imaging and procedures. TAVR procedures, cardiac MRIs, and nuclear stress tests almost always require pre-authorization. Check before you perform the service or you might not get paid at all.
NCCI bundling violations happen when you bill codes together that are not supposed to be billed together according to CMS National Correct Coding Initiative guidelines. Payers have automated systems that catch these immediately.
Documentation gaps in cath reports and ablation reports lead to denials or downcoding. If you billed for a comprehensive procedure but your report does not document all the components, the payer will downcode to a lesser procedure or deny entirely.
Best Practices for Clean Cardiology Claims
Invest in specialty-specific training for your coders. Cardiology is too complex to wing it.
Know your LCD and NCD policies for Medicare. These spell out exactly what diagnoses support what procedures.
Conduct quarterly audits of your coding accuracy. Find your own problems before payers do.
Use claim scrubbing technology to catch errors before claims go out.
Build strong relationships with your cardiologists so they understand documentation requirements.
When to Bring in Outside Help
Sometimes it makes sense to outsource your cardiology billing and coding to specialists who live and breathe this stuff every day.
If your denial rate is above 10 percent, you have a serious problem. Specialty billing companies like Sirius Solutions Global can often get that down to 5 percent or less through better coding accuracy and more aggressive follow-up on denied claims.
If you are not getting claims out the door fast enough, you are killing your cash flow. Revenue cycle delays cost you money every single day. Outside help can speed up your entire billing process significantly.
If you do not have in-house expertise in cardiology-specific coding, you are taking a huge risk. The learning curve is steep and the cost of mistakes is high. One major audit can wipe out months of revenue.
At Sirius Solutions Global, we specialize in complex specialty billing like cardiology. We know these codes inside and out. We stay current on every coding change. And we have the technology and expertise to maximize your reimbursement while keeping you compliant.
FAQs
What are the most commonly used CPT codes in cardiology?
The most common are office visit codes (99202-99215), ECG (93000), echocardiogram (93306), and stress tests (93015).
What ICD-10 codes justify ordering an echocardiogram?
Heart failure codes, valve disorders, cardiomyopathy, and arrhythmias all support ordering an echo.
What is CPT 93306 used for?
CPT 93306 is a complete transthoracic echocardiogram with 2D, M-mode, and Doppler evaluation.
How do I reduce claim denials in cardiology?
Use specific diagnosis codes, pair them correctly with procedures, verify authorization requirements, and ensure thorough documentation.
Do cardiology codes get updated every year?
Yes, CPT codes update annually on January 1st. ICD-10 codes update twice yearly in April and October.
Final Thoughts
Let’s be honest, Cardiology coding in 2026 isn’t getting any simpler.
Procedures are more advanced than ever, codes keep getting updated, and insurance companies are watching claims more closely than they used to. It can feel like you’re doing everything right… and still getting hit with denials or underpayments.
But here’s the good news:
