B17.9 ICD-10-CM Code: Acute viral hepatitis, unspecified
HCC Buddy Code Card
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FY 2026 Apr update / Certain infectious and parasitic diseases (A00-B99) / Viral hepatitis (B15-B19)
B17.9
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceAcute viral hepatitis, unspecified
A sudden viral liver infection where the specific type of hepatitis virus has not been identified or determined.
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
Official- Acute hepatitis NOS
- Acute infectious hepatitis NOS
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for B17.9 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for B17.9 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for B17.9 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for B17.9 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for B17.9 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for B17.9 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 B17.9 an HCC code?
No. B17.9 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
B17.9 is the ICD-10-CM diagnosis code for acute viral hepatitis, unspecified. A sudden viral liver infection where the specific type of hepatitis virus has not been identified or determined. B17.9 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering viral hepatitis (b15-b19).
B17.9 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.
This is a default code used when the hepatitis virus type is unknown or not yet confirmed.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for B17.9 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is a default code used when the hepatitis virus type is unknown or not yet confirmed
- •Update the code once the specific virus type is identified through testing