2026 ICD-10-CM Diagnosis Code B01Varicella [chickenpox]

ICD-10-CM Codes›A00–B99›B00-B09›B01

ICD-10-CM B01
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

B01 is a non-billable ICD-10-CM category code for varicella [chickenpox], so it cannot be submitted on claims. Use a more specific code from this category instead, such as B01.0, B01.11, B01.12, and B01.2.

Code Identity

ICD-10-CM Code
B01
Billable Status
No — Non-Billable Category
Code Describes
Varicella [chickenpox]
Chapter
B00-B09
Viral infections characterized by skin and mucous membrane lesions

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionB00-B09Viral infections characterized by skin and mucous membrane lesions
CategoryB01Varicella [chickenpox]
This CodeB01Varicella [chickenpox]

Specific Coding for Varicella [chickenpox]Overview

Non-specific codes like B01 require more characters. Use one of these billable codes instead:

  • Use B01.0 for Varicella meningitis

  • B01.1 for Varicella encephalitis, myelitis and encephalomyelitis

  • Use B01.11 for Varicella encephalitis and encephalomyelitis

  • Use B01.12 for Varicella myelitis

  • Use B01.2 for Varicella pneumonia

  • B01.8 for Varicella with other complications

  • Use B01.81 for Varicella keratitis

  • Use B01.89 for Other varicella complications

  • Use B01.9 for Varicella without complication

Patient EducationClinical

Chickenpox

Chickenpox is an infection caused by the varicella-zoster virus. Most cases are in children under age 15, but older children and adults can get it. It spreads very easily from one person to another.

Read the full article at MedlinePlus

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

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 B01Overview

Is B01 (Varicella [chickenpox]) a billable code?

No. This is a category header that groups the codes for varicella [chickenpox], and headers cannot be submitted on claims. Claims for varicella [chickenpox] need a more specific code from this category, such as B01.0, B01.11, and B01.12.