ICD-10 Code I44 – Atrioventricular and left bundle-branch block (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I44 – Atrioventricular and left bundle-branch block
What it is
I44 identifies disorders of conduction between the atria and ventricles, including atrioventricular block and left bundle-branch block. Use it when the record documents a conduction delay or block rather than an ischemic or structural heart diagnosis.
Clinical signs
Clinical features vary; refer to documentation. Common findings include ECG evidence of delayed or interrupted conduction, such as PR prolongation, dropped beats, or a widened QRS pattern with left bundle-branch block.
When to use this code
Use I44 when the provider documents AV block, left bundle-branch block, or a related conduction disorder as the confirmed diagnosis. It is appropriate for inpatient and outpatient coding when the abnormality is clinically relevant and not merely an incidental ECG comment. Check documentation if the type of block is unclear.
Do not use for
Do not use this code for nonspecific palpitations, chest pain, or other symptoms without a documented conduction block. If the note identifies a different arrhythmia or a more specific heart condition, code that diagnosis instead.
Coding tip
Capture the most specific conduction diagnosis documented, and verify whether the record distinguishes AV block from left bundle-branch block.