ICD-10 Code I45.2 – Bifascicular block (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I45.2 – Bifascicular block
What it is
Bifascicular block is a conduction abnormality involving two of the three main fascicles in the His-Purkinje system. It usually appears on ECG as a right bundle branch block with a fascicular block, or as a complete block of both left fascicles.
Clinical signs
Clinical features vary; refer to documentation. Many patients are asymptomatic, and the finding is often identified on electrocardiogram. Syncope, presyncope, or other conduction-related symptoms may be documented when the block is clinically significant.
When to use this code
Use this code when the provider documents bifascicular block by name or clearly describes the ECG pattern. It is appropriate for confirmed conduction disease noted during evaluation, monitoring, or follow-up. Code only when the diagnosis is established in the record.
Do not use for
Do not use this code for isolated right bundle branch block or a single fascicular block. If the documentation is unclear or only mentions an abnormal ECG without a diagnosis, check documentation.
Coding tip
Code the specific conduction defect documented by the clinician; if the ECG pattern is described instead of the diagnosis, verify the final interpretation.