Cardiology CPT Codes: Common Codes and Billing Rules

Cardiology practices bill from several parts of the CPT code set: office and hospital visits (E/M codes), the cardiovascular codes in the Medicine section for tests and catheter-based procedures (electrocardiograms, echocardiograms, stress tests, rhythm monitoring, cardiac catheterization and coronary interventions), Surgery section codes for procedures such as pacemaker and defibrillator implants, and Radiology codes for nuclear cardiology. Most of the diagnostic tests split into a professional component (the interpretation) and a technical component (the equipment and staff), so a large part of cardiology billing is reporting the right component for the setting. The rest is applying the bundling rules for catheterization, PCI and testing.

The rules below are Medicare's, from the National Correct Coding Initiative (NCCI) policy manual and the Physician Fee Schedule files. Commercial payers and Medicaid plans often follow NCCI but set their own policies, and many Medicare Administrative Contractors (MACs) publish local coverage determinations (LCDs) for cardiac tests. Payment varies by payer and locality; for Medicare, use the Physician Fee Schedule look-up.

Which cardiology codes are billed most often?

Common examples, described in our own words:

All of these codes are active in the 2026 Medicare fee schedule. Check the fee schedule file for each code's global period: in 2026 the catheterization and PCI codes above carry a 000 global period and pacemaker insertion (33208) carries 090. Codes are added, revised and deleted every year, so check the code set for the date of service.

How do professional and technical components work?

CMS gives every code a PC/TC indicator in the fee schedule file:

• Split codes (indicator 1), such as the echo and nuclear imaging codes. The complete (global) service is billed without a modifier. Modifier 26 reports the professional component only, and modifier TC the technical component only.
• Separate codes for each part. Some tests have their own codes instead of modifiers. For a routine ECG, 93000 is the complete service, 93005 the tracing only and 93010 the interpretation only. Modifiers 26 and TC can't be used with these codes. The stress test (93015–93018) and the ambulatory ECG codes work the same way.
• Physician services (indicator 0), such as catheterization and PCI codes billed by the physician, and visits, aren't split into components.

Bill only the component the practice actually furnished. When the practice interprets a study performed on someone else's equipment, it bills the professional component, not the complete service.

Which bundling rules catch cardiology claims?

The NCCI policy manual's cardiovascular section sets out rules that cardiology claims run into often:

• Catheterization and PCI include their access and imaging. Vascular access, catheter placement, injections, fluoroscopy and ECG rhythm strips are part of cardiac catheterization and coronary interventions, and ultrasound guidance during these procedures isn't separately reportable.
• Diagnostic angiography before a PCI. Coronary catheterization and angiography are included in a PCI. They may be reported separately only when a medically necessary diagnostic study comes before the intervention.
• One PCI code per vessel. Only one PCI code is reported for all interventions in one major coronary artery. The left anterior descending, circumflex and right coronary arteries each have up to two recognized branches for reporting; the left main and ramus intermedius have none. A lesion that extends from one vessel into another and is treated with one intervention gets one PCI code.
• Stress tests include their own history and exam. A brief history and exam related to the stress test are part of it. A visit on the same day is reported only if it is significant and separately identifiable, with modifier 25. The ECG strips and injections during the test aren't billed separately.
• Echo contrast. Injecting contrast for echocardiography isn't separately reportable.
• Doppler add-on codes. The complete transthoracic echo code 93306 already includes Doppler, and CMS's add-on code file doesn't list it as a primary code for the Doppler add-on codes 93320, 93321 and 93325.
• Device procedures. Catheter placement and fluoroscopy for pacemaker, defibrillator and electrophysiology procedures aren't billed separately; a cardiac catheterization is billed only if it was a separate, medically necessary service.

A modifier such as 59 or XU is used only when the record documents a distinct service; the CO-97 guide covers how bundling denials arise and when those modifiers apply.

What about office visits and procedures on the same day?

Office and hospital visits are coded by medical decision making or total time, like any other specialty; the 99214 guide explains how. A visit on the same day as a procedure with a global period is paid separately only when the record supports modifier 25 (a significant, separately identifiable visit) or, before a major procedure, modifier 57 (the decision to operate). The CY 2027 Physician Fee Schedule proposed rule (July 2026) proposes reducing payment when an office visit is billed on the same day as a procedure with a global period; check the final rule before January 2027.

Where do cardiology claims go wrong?

• The wrong component, such as billing a complete service for a hospital-based study the practice only read.
• Bundled services billed separately: fluoroscopy or ultrasound guidance with catheterization, ECG strips with a stress test, Doppler add-ons with 93306.
• PCI coding that counts branches or segments the NCCI rules don't recognize separately.
• Coverage and medical necessity: repeat echocardiograms or monitoring without the indications a MAC's LCD requires, and diagnosis codes that don't match the order. CPT vs ICD-10 codes explains how diagnosis codes support a claim.
• Prior authorization for advanced imaging and some procedures, which many commercial plans require; each plan keeps its own list.

For billing support, see Highview's physician billing service, and billing by specialty.

Sources

• CMS, Medicare NCCI Policy Manual, Chapter 11 (effective January 1, 2026), section I (cardiovascular services): catheterization and PCI bundling, PCI vessels and branches, stress tests, echo contrast, device procedures.
• CMS, PFS Relative Value Files, RVU26D: 2026 status, global periods and PC/TC indicators for the codes listed, and the definitions of the PC/TC indicators.
• CMS, Medicare NCCI Add-on Code Edits (effective October 1, 2026): primary codes for 93320, 93321 and 93325.
• CMS, Global Surgery booklet, MLN907166 (December 2025): modifiers 25 and 57.
• CMS, CY 2027 Physician Fee Schedule proposed rule fact sheet: proposed same-day visit and procedure payment reduction.
• CMS Medicare Coverage Database, for example LCD L33577, Transthoracic Echocardiography and LCD L33557, Cardiac Catheterization and Coronary Angiography (Wellpoint Federal): examples of MAC coverage policies for cardiac tests.
• CMS, Search the Physician Fee Schedule.