2026 ICD-10-CM Diagnosis Code B18.1Chronic viral hepatitis B without delta-agent

ICD-10-CM Codes›A00–B99›B15-B19›B18

ICD-10-CM B18.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

B18.1 is a billable ICD-10-CM diagnosis code for chronic viral hepatitis B without delta-agent. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 441 through 443. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Hepatitis and Viral infection.

Code Identity

ICD-10-CM Code
B18.1
Billable Status
Yes — Valid for Submission
Code Describes
Chronic viral hepatitis B without delta-agent
Short Description
Chronic viral hepatitis B without delta-agent
Same as the full description in the CMS dataset.
Parent Code
B18
Chronic viral hepatitis

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionB15-B19Viral hepatitis
CategoryB18Chronic viral hepatitis
This CodeB18.1Chronic viral hepatitis B without delta-agent

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Chronic active hepatitis
  • Chronic active type B viral hepatitis
  • Chronic active viral hepatitis
  • Chronic aggressive type B viral hepatitis
  • Chronic aggressive viral hepatitis
  • Chronic hepatitis B co-occurrent with hepatitis C and hepatitis D
  • Chronic hepatitis B during pregnancy
  • Chronic persistent hepatitis
  • Chronic persistent type B viral hepatitis
  • Chronic persistent viral hepatitis
  • Chronic type B viral hepatitis
  • Chronic viral hepatitis B with hepatitis D
  • Chronic viral hepatitis B without delta-agent
  • Hepatic coma due to chronic hepatitis B
  • Hepatic coma due to viral hepatitis B
  • Hepatitis B and hepatitis C
  • Hepatitis B carrier
  • Liver disorder in pregnancy
  • Occult chronic type B viral hepatitis
  • Viral hepatitis carrier
  • Viral hepatitis complicating pregnancy, childbirth and the puerperium
  • Viral hepatitis D
  • Viral hepatitis in mother complicating pregnancy

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Carrier of viral hepatitis B
  • Chronic (viral) hepatitis B

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Carrier(suspected) of
      • HB (c) (s)-AG
    • Carrier(suspected) of
      • hepatitis (viral)
        • B surface antigen (HBsAg)
    • Hepatitis
      • B
        • chronic
    • Hepatitis
      • viral, virus
        • chronic
          • type
            • B
    • Hepatitis
      • viral, virus
        • type
          • B
            • chronic
    • Serum
      • hepatitis
        • carrier (suspected) of

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INF007
Hepatitis
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR INF008
Viral infection
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Hepatitis B

Hepatitis is inflammation of the liver. Inflammation is swelling that happens when tissues of the body are injured or infected. It can damage your liver. This swelling and damage can affect how well your liver functions.

The full article covers:

  • What is hepatitis?
  • What is hepatitis B?
  • What causes hepatitis B?
  • Who is at risk for hepatitis B?
  • What are the symptoms of hepatitis B?
  • What other problems can hepatitis B cause?
  • How is hepatitis B diagnosed?
  • What are the treatments for hepatitis B?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert B18.1 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
070.32 Hpt B chrn wo cm wo dlta
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About B18.1Overview

Is B18.1 (Chronic viral hepatitis) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report chronic viral hepatitis B without delta-agent on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does B18.1 group to?

When chronic viral hepatitis B without delta-agent is the principal diagnosis on an inpatient stay, it groups to MS-DRG 441, 442, 443, with relative weights from 0.6997 to 1.7947 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of B18.1?

Under the General Equivalence Mappings, chronic viral hepatitis B without delta-agent converts to ICD-9-CM 070.32 (hpt B chrn wo cm wo dlta). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.