ICD-10 Code I44.7 – Left bundle-branch block, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I44.7 – Left bundle-branch block, unspecified
What it is
Left bundle-branch block is a conduction abnormality in which electrical impulses travel abnormally through the heart’s left bundle branch. The “unspecified” code is used when documentation identifies LBBB but does not further define the type.
Clinical signs
Clinical features vary; refer to documentation. LBBB is typically identified on ECG by a widened QRS pattern and characteristic changes in ventricular depolarization.
When to use this code
Use I44.7 when the provider documents left bundle-branch block without additional detail, such as incomplete or intermittent terminology. It also fits when the record confirms LBBB on ECG and no more specific conduction diagnosis is stated. Check documentation if another cardiac condition is the primary reason for the visit.
Do not use for
Do not use this code for right bundle-branch block, nonspecific intraventricular conduction delay, or other arrhythmias. If the chart specifies a different bundle-branch pattern, code that documented condition instead.
Coding tip
Code the exact conduction abnormality documented; if the record says “left bundle-branch block” with no qualifiers, I44.7 is appropriate.