B01 ICD-10-CM Code: Varicella [chickenpox]
Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.
Coder workflow for B01
MedCoder structured workflow — derived from this code’s own official record
Before you code B01
- B01 is not reportable as written. Select the more specific code beneath it that the documentation supports. Codes are reported to the highest level of specificity the classification provides (Guidelines I.B.2).
ReviewB01.0, B01.1, B01.2, B01.8, B01.9
See the relationships section · Guide: How to choose an ICD-10-CM code →
Choose the right path
- Does the documentation support one of the more specific codes beneath B01?
Yes → Select that code and continue the checks below on its own page.
No → B01 cannot be reported as written; query for the specificity its subcategory needs.
Consider B01. Then confirm the code is valid for the date of service in the Verify section.
Documentation check
- The provider’s diagnostic statement
- Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.
Code Overview
MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.
Verify Before Coding
From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.
Relationships & Classification
MedCoder structured relationships — computed from published CMS and AHRQ datasets
Other codes that name B01 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.
Referenced by 1 Excludes2 note: B10 — Other human herpesviruses.
These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.
Referenced by 1 Code First instruction: H67 — Otitis media in diseases classified elsewhere.
Each of these codes carries a Code First note naming this condition — when that code is reported, THIS code is sequenced first, ahead of it.
Contextual Map
Every relationship of B01 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.
Run B01 with these 2 related codes in Claim Check
Hierarchy
- A00-B99 — Chapter 1: Certain Infectious and Parasitic Diseases (A00-B99) (A00-B99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- B00-B09 — Viral infections characterized by skin and mucous membrane lesions[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
Referenced by Excludes2 notes
- B10 — Other human herpesviruses[Excludes2]: “human herpesvirus 3 (B01.-, B02.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
Referenced by Code First instructions
- H67 — Otitis media in diseases classified elsewhere[Code First]: “viral disease NEC (B00-B34)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
Nearest codes (9)
- B01.0 — Varicella meningitis[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- B01.1 — Varicella encephalitis, myelitis and encephalomyelitis[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- B01.11 — Varicella encephalitis and encephalomyelitis[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- B01.12 — Varicella myelitis[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- B01.2 — Varicella pneumonia[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- B01.8 — Varicella with other complications[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- B01.81 — Varicella keratitis[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- B01.89 — Other varicella complications[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- and 1 more
Change history
- FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016
Common coding questions
Can B01 be billed directly?
No. B01 (Varicella [chickenpox]) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.
Sources for this page
Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.
- Code, title, tabular notes and index terms Official source data
- CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
- Claim edits Official source data
- CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
- Change history and date-of-service validity Official source data
- CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
- Comparisons, relationships and the contextual map MedCoder structured relationship
- Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
- Summary and FAQ answers MedCoder explanation
- Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.
Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates
Cite this page
Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.
MedCoder.ai. "B01 — Varicella [chickenpox]." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/b01-varicella-chickenpox
Change history
- FY2016 — October 1, 2015In the code set at ICD-10-CM adoptionVaricella [chickenpox]
No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.
Nearest Codes in This Family
Official ICD-10-CM classifications closest to B01 in its code family, with their registry titles.
- B01.0 — Varicella meningitis
- B01.1 — Varicella encephalitis, myelitis and encephalomyelitis
- B01.11 — Varicella encephalitis and encephalomyelitis
- B01.12 — Varicella myelitis
- B01.2 — Varicella pneumonia
- B01.8 — Varicella with other complications
- B01.81 — Varicella keratitis
- B01.89 — Other varicella complications
- B01.9 — Varicella without complication