ICD-10 Code I44.6 – Other and unspecified fascicular block (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I44.6 – Other and unspecified fascicular block
What it is
I44.6 identifies a conduction abnormality in the fascicles of the heart’s electrical system. Use it when the record states other or unspecified fascicular block without a more specific subtype.
Clinical signs
Clinical features vary; refer to documentation. This diagnosis is usually supported by an ECG showing a fascicular conduction delay or block, often described in the left anterior or left posterior fascicle.
When to use this code
Use I44.6 when the provider documents other fascicular block or fascicular block without further detail. It also fits when the ECG interpretation names a fascicular block, but the note does not specify the exact fascicle. Check documentation if the rhythm issue is part of a broader conduction disorder.
Do not use for
Do not use this code for bundle branch block, atrioventricular block, or nonspecific ECG abnormalities. If the record identifies a more specific conduction defect, code that diagnosis instead.
Coding tip
Code only what the provider documents; if “fascicular block” appears without detail, I44.6 is the appropriate unspecified option.