ICD-10 B18.1
Billable / Specific HCC v28: 29 CCChronic viral hepatitis B without delta-agent
About ICD-10-CM B18.1
ICD-10-CM code B18.1 represents Chronic viral hepatitis B without delta-agent. This is a billable/specific code in the Infectious and Parasitic Diseases chapter (block B18). The 2026 edition of ICD-10-CM B18.1 became effective on October 1, 2025.
Coding Tips for B18.1
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
B18.1 is a CMS-HCC v28 risk-adjustment code (category 29). To count for the patient Risk Adjustment Factor (RAF), document the diagnosis with MEAT language each calendar year: Monitored, Evaluated, Assessed, Treated. A diagnosis on the problem list alone does not satisfy CMS RADV audit standards. Include the diagnosis in the assessment with current status and current treatment plan.
B18.1 is designated CC for MS-DRG grouping. On inpatient claims, this code can shift the DRG to the with-CC variant when documented as a present-on-admission secondary diagnosis. Hospital CDI programs flag CC opportunities during chart review. Failure to capture this code may leave 30 to 80 percent of the inpatient stay revenue unrealized.
Inclusion Terms / Approximate Synonyms
Clinical terms and conditions classified under B18.1. Per CMS ICD-10-CM Tabular 2026.
- Carrier of viral hepatitis B
- Chronic (viral) hepatitis B
Medicare Advantage HCC Impact
Capture this diagnosis annually for accurate risk adjustment. Missed HCC captures are the #1 revenue leak in Medicare Advantage risk programs.
Inpatient DRG Impact, CC
codes Chronic viral hepatitis B without delta-agent. As a Complication/Comorbidity (CC), this contributes to DRG severity adjustment when documented alongside the principal diagnosis.
Medicare LCD Coverage for B18.1
Local Coverage Determinations (LCDs) from CMS MACs that list B18.1 as a covered diagnosis.
Showing top 10 of 165 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing B18.1.
4 Aetna
5 Medicare
CPT Codes Commonly Billed with B18.1
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 0031U CMS LCD: Billing and Coding: Pharmacogenomics Testing CMS LCD
- 0173U CMS LCD: Billing and Coding: Pharmacogenomics Testing CMS LCD
- 0423U CMS LCD: Billing and Coding: Pharmacogenomics Testing CMS LCD
- 81407 CMS LCD: Billing and Coding: Pharmacogenomics Testing CMS LCD
- 0349U CMS LCD: Billing and Coding: Pharmacogenomics Testing CMS LCD
- 81408 CMS LCD: Billing and Coding: Pharmacogenomics Testing CMS LCD
- 0175U CMS LCD: Billing and Coding: Pharmacogenomics Testing CMS LCD
- 0032U CMS LCD: Billing and Coding: Pharmacogenomics Testing CMS LCD
- 81220 CMS LCD: Billing and Coding: Pharmacogenomics Testing CMS LCD
- 0392U CMS LCD: Billing and Coding: Pharmacogenomics Testing CMS LCD
Convert B18.1 to ICD-9-CM
Per CMS General Equivalence Mappings (GEMs), useful for legacy data review and historical claim analysis.
| ICD-10 | ICD-9 | Mapping Flags |
|---|---|---|
| B18.1 | 07032 | 10000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To B18.1
Other codes in section B15-B19 (Viral hepatitis).
ICD-10 B18.1, Billing FAQ
Is ICD-10 code B18.1 billable? +
Yes, B18.1 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
What other names or terms map to B18.1? +
ICD-10 B18.1 includes: Carrier of viral hepatitis B; Chronic (viral) hepatitis B.
Does B18.1 affect Medicare Advantage HCC risk adjustment? +
Yes. B18.1 maps to CMS-HCC v28 category 29. Capture this diagnosis annually for accurate Medicare Advantage risk score.
Is B18.1 a CC or MCC for inpatient DRG? +
Yes, this code is designated as CC. Documenting as a secondary diagnosis on inpatient claims can shift the DRG to a higher-weighted category.
What CPT codes are commonly billed with B18.1? +
Procedures frequently paired with B18.1 include: 0031U, 0173U, 0423U, 81407, 0349U.
What ICD-9 codes does B18.1 map to? +
Per CMS GEMs, B18.1 maps to ICD-9 codes: 07032. Useful for legacy data review and historical claim analysis.
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on May 31, 2026.
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