The ICD-10-CM code block B00–B09 covers viral infections that present with characteristic skin and mucous membrane lesions, including herpes viral infections, varicella (chickenpox), zoster (shingles), viral warts, and other viral diseases.
These conditions are common in outpatient, dermatology, pediatrics, family medicine, and infectious disease practices—and require accurate code selection to ensure proper documentation, billing, and reimbursement.
At Allzone Management Services, our experienced medical coders ensure precise mapping of infectious disease codes, compliance with CDC and ICD-10-CM guidelines, and correct sequencing to minimize denials and maximize reimbursement.
ICD-10-CM Code Range Breakdown (B00–B09)
### B00 — Herpesviral [Herpes Simplex] Infections
Covers HSV-1 and HSV-2 infections affecting skin, mucosa, eyes, and nervous system.
Common Codes
| Code | Description |
| B00.0 | Eczema herpeticum |
| B00.1 | Herpesviral vesicular dermatitis |
| B00.2 | Herpetic gingivostomatitis/pharyngotonsillitis |
| B00.3 | Herpesviral meningitis |
| B00.4 | Herpesviral encephalitis |
| B00.5 | Herpesviral ocular disease |
| B00.7 | Disseminated herpesviral infection |
| B00.9 | Unspecified herpesviral infection |
Coding Tips
- Identify specific site (skin, eye, CNS, mucosal areas).
- Coders must NOT use B00.X codes for genital herpes—instead use A60.X.
- Document complications (e.g., encephalitis, conjunctivitis).
### B01 — Varicella (Chickenpox)
Caused by the varicella-zoster virus (VZV).
Common Codes
| Code | Description |
| B01.0 | Varicella meningitis |
| B01.1 | Varicella encephalitis |
| B01.2 | Varicella pneumonia |
| B01.81 | Varicella with other complications |
| B01.9 | Varicella without complications |
Coding Tips
- Use B01.9 only if the provider does not document specific complications.
- Identify associated conditions (pneumonia, encephalitis, meningitis).
- Immunocompromised patients may require additional Z-codes.
### B02 — Zoster (Shingles)
Reactivation of VZV—common in older adults and immunocompromised individuals.
Key Clinical Features
- Painful dermatomal rash
- Post-herpetic neuralgia
- Possible ophthalmic involvement
Common Codes
| Code | Description |
| B02.0 | Zoster encephalitis |
| B02.1 | Zoster meningitis |
| B02.2 | Zoster with other nervous system complications |
| B02.3 | Zoster ophthalmicus |
| B02.7 | Disseminated zoster |
| B02.9 | Zoster without complications |
Coding Guidelines
- Code B02.29 for post-herpetic neuralgia (PHN).
- Do NOT code varicella (B01) for shingles.
- Document if the rash is:
- disseminated
- ophthalmic
- involves CNS
- includes PHN
### B03 — Smallpox
Although eradicated, ICD-10-CM maintains this code for bioterrorism preparedness.
| Code | Description |
| B03 | Smallpox |
Coding Notes
- Rarely encountered
- Must be supported by public health documentation
### B04 — Monkeypox
Used for cases of orthopoxvirus monkeypox infection.
| Code | Description |
| B04 | Monkeypox |
Coding Notes
- Added to support outbreak tracking
- Ensure documentation of lab-confirmed or clinically diagnosed monkeypox
### B05 — Measles
Covers classic and complicated measles.
Common Codes
| Code | Description |
| B05.0 | Measles complicated by encephalitis |
| B05.1 | Measles pneumonia |
| B05.2 | Measles otitis media |
| B05.81 | Measles with other complications |
| B05.9 | Measles without complications |
Key Documentation
- Exposure history
- Complications
- Vaccination status (Z23 or Z28 codes if relevant)
### B06 — Rubella (German Measles)
Covers congenital and acquired rubella infections.
Common Codes
| Code | Description |
| B06.0 | Rubella with neurological complications |
| B06.81 | Rubella with other complications |
| B06.9 | Rubella without complications |
### B07 — Viral Warts
Common in dermatology and primary care coding.
Common Codes
| Code | Description |
| B07.0 | Plantar wart |
| B07.1 | Viral warts, unspecified |
| B07.8 | Other viral warts |
| B07.9 | Unspecified viral wart |
Documentation Tips
- Specify type: common, plantar, genital (A63.0), flat
- Identify if recurrent or resistant
### B08 — Other Viral Infections with Skin and Mucous Membrane Lesions
Includes conditions like:
| Code | Description |
| B08.1 | Molluscum contagiosum |
| B08.2 | Orf virus infection |
| B08.3 | Exanthema subitum (roseola) |
| B08.4 | Enteroviral vesicular stomatitis with exanthem |
| B08.5 | Enteroviral vesicular pharyngitis |
| B08.8 | Other specified viral infections |
| B08.9 | Unspecified viral infection |
### B09 — Unspecified Viral Infection with Skin and Mucous Membrane Lesions
| Code | Description |
| B09 | Unspecified viral infection with skin and mucous membrane lesions |
Use B09 Only When:
- No specific virus is identified
- Documentation does not indicate type of lesion
- Symptoms match this category but are nonspecific
Documentation Requirements by Providers
To ensure accurate coding under B00–B09, providers must document:
- Specific virus (HSV, VZV, measles, rubella, etc.)
- Exact anatomical site impacted
- Presence of complications (encephalitis, pneumonia, meningitis, PHN)
- Severity and stage (acute, disseminated, ophthalmic involvement)
- Diagnostic confirmation (PCR, culture)
- Immunization status when relevant
Common Coding Errors and How to Avoid Them
| Error | Why It Happens | How Allzone Prevents It |
| Using unspecified codes unnecessarily | Missing documentation | Clinical validation and coder queries |
| Confusing shingles with chickenpox | Similar rash patterns | Verification with patient age & history |
| Incorrect sequencing of complications | Lack of coding expertise | Senior QC review |
| Missing PHN for shingles | Underdocumented symptom | Provider education tools |
| Using A-codes instead of B-codes | Viral specificity confusion | Automated code checks |
Why Choose Allzone for ICD-10-CM Infectious Disease Coding?
Allzone Management Services ensures:
- Accurate ICD-10-CM coding across all specialties
- 100% HIPAA compliance
- Reduction in denials through coding accuracy
- End-to-end Revenue Cycle Management (RCM) support
- Experienced coders trained in complex infectious disease classification
- Faster turnaround and improved cash flow for healthcare providers
Our team stays updated with CDC coding changes, ICD-10-CM annual updates, and payer-specific billing rules to ensure clean claims and optimized reimbursement.
Conclusion
The ICD-10-CM code range B00–B09 covers some of the most common viral infections affecting the skin and mucous membranes. Proper selection, linked complication coding, and clear documentation are essential for accurate billing and clinical clarity. With Allzone’s expertise in medical coding and revenue cycle management, providers can ensure maximum accuracy, greater revenue integrity, and fewer denials.