ICD-10 Code I45.0 – Right fascicular block (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I45.0 – Right fascicular block
What it is
Right fascicular block is a conduction abnormality involving the right-sided branch of the heart’s electrical system. It can be seen on an ECG and may be isolated or occur with other cardiac disease.
Clinical signs
Clinical features vary; refer to documentation. ECG findings typically show a pattern consistent with right fascicular conduction delay, and the diagnosis is usually made from the tracing rather than symptoms alone.
When to use this code
Use I45.0 when the provider documents right fascicular block or right-sided fascicular conduction block. Apply it when the ECG interpretation or final assessment identifies this specific conduction defect. If the note only says “abnormal ECG,” check documentation.
Do not use for
Do not use this code for nonspecific rhythm changes, bundle branch block without fascicular involvement, or historical findings not confirmed in the current record. Check documentation if the exact conduction defect is unclear.
Coding tip
Code the specific conduction abnormality named by the provider, and do not infer right fascicular block from an ECG pattern alone unless it is documented.