I44.4 Left anterior fascicular block

Billable ICD-10-CM code, FY2026.

MS-DRG index

Defines the logic of DRG(s) 308-310 in MDC 05.

Approximate ICD-9-CM (GEMs)

• 426.2 Left bundle branch hemiblock (approximate)

Medicare Code Edits (MCE v43.1 (April 2026))

• Questionable admission: Some diagnoses are not usually sufficient justification for admission to an acute care hospital when reported as principal diagnosis.

Diagnosis Index entries for I44.4

• Block, blocked › bundle-branch (complete) (false) (incomplete) › left › hemiblock › anterior
• Block, blocked › fascicular (left) › anterior

Nearby codes

• I44.1 Atrioventricular block, second degree
• I44.2 Atrioventricular block, complete
• I44.3 Other and unspecified atrioventricular block
• I44.30 Unspecified atrioventricular block
• I44.39 Other atrioventricular block
• I44.4 Left anterior fascicular block (this code)
• I44.5 Left posterior fascicular block
• I44.6 Other and unspecified fascicular block
• I44.60 Unspecified fascicular block
• I44.69 Other fascicular block
• I44.7 Left bundle-branch block, unspecified