I44.4 ICD-10-CM Code: Left anterior fascicular block
HCC Buddy Code Card
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FY 2026 Apr update / Diseases of the circulatory system (I00-I99) / Other forms of heart disease (I30-I5A)
I44.4
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceLeft anterior fascicular block
A heart conduction problem where electrical signals are blocked in the anterior branch of the left bundle, affecting how the heart's lower chambers contract.
CMS-HCC V28
00
RAF 0
CMS-HCC V24
00
RAF 0
ACA/HHS
00
RAF 0
ESRD/PACE
00
RAF 0
RXHCC
00
RAF 0
Code Trumping
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Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for I44.4 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for I44.4 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for I44.4 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for I44.4 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for I44.4 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for I44.4 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for I44.4 in this effective period.
Buddy Documentation Tip
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
Is I44.4 an HCC code?
No. I44.4 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).
What This Code Means
I44.4 is the ICD-10-CM diagnosis code for left anterior fascicular block. A heart conduction problem where electrical signals are blocked in the anterior branch of the left bundle, affecting how the heart's lower chambers contract. I44.4 sits in the ICD-10-CM chapter for diseases of the circulatory system (i00-i99), within the section covering other forms of heart disease (i30-i5a).
I44.4 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.
Verify documentation specifies 'anterior' fascicular block to distinguish from posterior fascicular block (I44.5).
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for I44.4 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify documentation specifies 'anterior' fascicular block to distinguish from posterior fascicular block (I44.5)
- •This is often an incidental finding on EKG; confirm clinical significance and any associated symptoms